Rework Mail System (#3710)

* New `/mail sendtemp <time diff> <message>` command to send mail that will self-destruct after time diff.
* New `/mail clear <number>` command to clear a specific mail item.
* `/mail read` now tracks which mails you read and won't nag you about them.
* A bunch of other flexibility since we store actual data instead of strings

Essentials/src/main/java/com/earth2me/essentials/Console.java

@@ -6,6 +6,8 @@ import org.bukkit.Server;
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
 
+import java.util.UUID;
+
 import static com.earth2me.essentials.I18n.tl;
 
 public final class Console implements IMessageRecipient {
@@ -46,6 +48,11 @@ public final class Console implements IMessageRecipient {
         return Console.NAME;
     }
 
+    @Override
+    public UUID getUUID() {
+        return null;
+    }
+
     @Override
     public String getDisplayName() {
         return Console.DISPLAY_NAME;

Essentials/src/main/java/com/earth2me/essentials/Essentials.java

@@ -82,6 +82,7 @@ import net.ess3.provider.providers.PaperRecipeBookListener;
 import net.ess3.provider.providers.PaperSerializationProvider;
 import net.ess3.provider.providers.PaperServerStateProvider;
 import net.essentialsx.api.v2.services.BalanceTop;
+import net.essentialsx.api.v2.services.mail.MailService;
 import org.bukkit.Bukkit;
 import org.bukkit.Server;
 import org.bukkit.World;
@@ -147,6 +148,7 @@ public class Essentials extends JavaPlugin implements net.ess3.api.IEssentials {
     private transient UserMap userMap;
     private transient BalanceTopImpl balanceTop;
     private transient ExecuteTimer execTimer;
+    private transient MailService mail;
     private transient I18n i18n;
     private transient MetricsWrapper metrics;
     private transient EssentialsTimer timer;
@@ -204,6 +206,7 @@ public class Essentials extends JavaPlugin implements net.ess3.api.IEssentials {
         LOGGER.log(Level.INFO, tl("usingTempFolderForTesting"));
         LOGGER.log(Level.INFO, dataFolder.toString());
         settings = new Settings(this);
+        mail = new MailServiceImpl(this);
         userMap = new UserMap(this);
         balanceTop = new BalanceTopImpl(this);
         permissionsHandler = new PermissionsHandler(this, false);
@@ -277,6 +280,9 @@ public class Essentials extends JavaPlugin implements net.ess3.api.IEssentials {
             confList.add(settings);
             execTimer.mark("Settings");
 
+            mail = new MailServiceImpl(this);
+            execTimer.mark("Init(Mail)");
+
             userMap = new UserMap(this);
             confList.add(userMap);
             execTimer.mark("Init(Usermap)");
@@ -1159,6 +1165,11 @@ public class Essentials extends JavaPlugin implements net.ess3.api.IEssentials {
         return timer;
     }
 
+    @Override
+    public MailService getMail() {
+        return mail;
+    }
+
     @Override
     public List<String> getVanishedPlayers() {
         return Collections.unmodifiableList(new ArrayList<>(vanishedPlayers));

Essentials/src/main/java/com/earth2me/essentials/EssentialsPlayerListener.java

@@ -364,8 +364,7 @@ public class EssentialsPlayerListener implements Listener {
                 }
 
                 if (!ess.getSettings().isCommandDisabled("mail") && user.isAuthorized("essentials.mail")) {
-                    final List<String> mail = user.getMails();
+                    if (user.getUnreadMailAmount() == 0) {
-                    if (mail.isEmpty()) {
                         if (ess.getSettings().isNotifyNoNewMail()) {
                             user.sendMessage(tl("noNewMail")); // Only notify if they want us to.
                         }

Essentials/src/main/java/com/earth2me/essentials/EssentialsUpgrade.java

@@ -7,7 +7,9 @@ import com.earth2me.essentials.craftbukkit.BanLookup;
 import com.earth2me.essentials.utils.StringUtil;
 import com.google.common.base.Charsets;
 import com.google.common.collect.Maps;
+import com.google.gson.reflect.TypeToken;
 import net.ess3.api.IEssentials;
+import net.essentialsx.api.v2.services.mail.MailMessage;
 import org.bukkit.BanList;
 import org.bukkit.Bukkit;
 import org.bukkit.Location;
@@ -146,6 +148,46 @@ public class EssentialsUpgrade {
         ess.getLogger().info("To rerun the conversion type /essentials uuidconvert");
     }
 
+    public void convertMailList() {
+        if (doneFile.getBoolean("updateUsersMailList", false)) {
+            return;
+        }
+
+        final File userdataFolder = new File(ess.getDataFolder(), "userdata");
+        if (!userdataFolder.exists() || !userdataFolder.isDirectory()) {
+            return;
+        }
+        final File[] userFiles = userdataFolder.listFiles();
+        for (File file : userFiles) {
+            if (!file.isFile() || !file.getName().endsWith(".yml")) {
+                continue;
+            }
+            final EssentialsConfiguration config = new EssentialsConfiguration(file);
+            try {
+                config.load();
+                if (config.hasProperty("mail") && config.isList("mail")) {
+                    final ArrayList<MailMessage> messages = new ArrayList<>();
+                    for (String mailStr : Collections.synchronizedList(config.getList("mail", String.class))) {
+                        if (mailStr == null) {
+                            continue;
+                        }
+                        messages.add(new MailMessage(false, true, null, null, 0L, 0L, mailStr));
+                    }
+
+                    config.removeProperty("mail");
+                    config.setExplicitList("mail", messages, new TypeToken<List<MailMessage>>() {}.getType());
+                    config.blockingSave();
+                }
+            } catch (RuntimeException ex) {
+                LOGGER.log(Level.INFO, "File: " + file);
+                throw ex;
+            }
+        }
+        doneFile.setProperty("updateUsersMailList", true);
+        doneFile.save();
+        LOGGER.info("Done converting mail list.");
+    }
+
     public void convertStupidCamelCaseUserdataKeys() {
         if (doneFile.getBoolean("updateUsersLegacyPathNames", false)) {
             return;
@@ -820,5 +862,6 @@ public class EssentialsUpgrade {
         repairUserMap();
         convertIgnoreList();
         convertStupidCamelCaseUserdataKeys();
+        convertMailList();
     }
 }

Essentials/src/main/java/com/earth2me/essentials/IEssentials.java

@@ -18,6 +18,7 @@ import net.ess3.provider.SpawnerBlockProvider;
 import net.ess3.provider.SpawnerItemProvider;
 import net.ess3.provider.SyncCommandsProvider;
 import net.essentialsx.api.v2.services.BalanceTop;
+import net.essentialsx.api.v2.services.mail.MailService;
 import org.bukkit.Server;
 import org.bukkit.World;
 import org.bukkit.command.Command;
@@ -120,6 +121,8 @@ public interface IEssentials extends Plugin {
 
     EssentialsTimer getTimer();
 
+    MailService getMail();
+
     /**
      * Get a list of players who are vanished.
      *

Essentials/src/main/java/com/earth2me/essentials/IUser.java

@@ -6,12 +6,15 @@ import com.earth2me.essentials.config.entities.CommandCooldown;
 import net.ess3.api.ITeleport;
 import net.ess3.api.MaxMoneyException;
 import net.ess3.api.events.AfkStatusChangeEvent;
+import net.essentialsx.api.v2.services.mail.MailMessage;
+import net.essentialsx.api.v2.services.mail.MailSender;
 import org.bukkit.Location;
 import org.bukkit.Material;
 import org.bukkit.block.Block;
 import org.bukkit.entity.Player;
 
 import java.math.BigDecimal;
+import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
 import java.util.Map;
@@ -148,10 +151,22 @@ public interface IUser {
 
     String getFormattedJailTime();
 
+    @Deprecated
     List<String> getMails();
 
+    @Deprecated
     void addMail(String mail);
 
+    void sendMail(MailSender sender, String message);
+
+    void sendMail(MailSender sender, String message, long expireAt);
+
+    ArrayList<MailMessage> getMailMessages();
+
+    void setMailList(ArrayList<MailMessage> messages);
+
+    int getMailAmount();
+
     boolean isAfk();
 
     @Deprecated

Essentials/src/main/java/com/earth2me/essentials/MailServiceImpl.java

@@ -0,0 +1,53 @@
+package com.earth2me.essentials;
+
+import net.ess3.api.IUser;
+import net.essentialsx.api.v2.services.mail.MailService;
+import net.essentialsx.api.v2.services.mail.MailMessage;
+import net.essentialsx.api.v2.services.mail.MailSender;
+import org.bukkit.plugin.ServicePriority;
+
+import java.text.SimpleDateFormat;
+import java.util.ArrayList;
+import java.util.Date;
+
+import static com.earth2me.essentials.I18n.tl;
+
+public class MailServiceImpl implements MailService {
+    private final transient ThreadLocal<SimpleDateFormat> df = ThreadLocal.withInitial(() -> new SimpleDateFormat("yyyy/MM/dd HH:mm"));
+
+    public MailServiceImpl(IEssentials ess) {
+        ess.getServer().getServicesManager().register(MailService.class, this, ess, ServicePriority.Normal);
+    }
+
+    @Override
+    public void sendMail(IUser recipient, MailSender sender, String message) {
+        sendMail(recipient, sender, message, 0L);
+    }
+
+    @Override
+    public void sendMail(IUser recipient, MailSender sender, String message, long expireAt) {
+        sendMail(recipient, new MailMessage(false, false, sender.getName(), sender.getUUID(), System.currentTimeMillis(), expireAt, message));
+    }
+
+    @Override
+    public void sendLegacyMail(IUser recipient, String message) {
+        sendMail(recipient, new MailMessage(false, true, null, null, 0L, 0L, message));
+    }
+
+    private void sendMail(IUser recipient, MailMessage message) {
+        final ArrayList<MailMessage> messages = recipient.getMailMessages();
+        messages.add(0, message);
+        recipient.setMailList(messages);
+    }
+
+    @Override
+    public String getMailLine(MailMessage mail) {
+        final String message = mail.getMessage();
+        if (mail.isLegacy()) {
+            return tl("mailMessage", message);
+        }
+
+        final String expire = mail.getTimeExpire() != 0 ? "Timed" : "";
+        return tl((mail.isRead() ? "mailFormatNewRead" : "mailFormatNew") + expire, df.get().format(new Date(mail.getTimeSent())), mail.getSenderUsername(), message);
+    }
+}

Essentials/src/main/java/com/earth2me/essentials/User.java

@@ -5,11 +5,11 @@ import com.earth2me.essentials.economy.EconomyLayer;
 import com.earth2me.essentials.economy.EconomyLayers;
 import com.earth2me.essentials.messaging.IMessageRecipient;
 import com.earth2me.essentials.messaging.SimpleMessageRecipient;
-import com.earth2me.essentials.utils.TriState;
 import com.earth2me.essentials.utils.DateUtil;
 import com.earth2me.essentials.utils.EnumUtil;
 import com.earth2me.essentials.utils.FormatUtil;
 import com.earth2me.essentials.utils.NumberUtil;
+import com.earth2me.essentials.utils.TriState;
 import com.earth2me.essentials.utils.VersionUtil;
 import com.google.common.collect.Lists;
 import net.ess3.api.IEssentials;
@@ -19,6 +19,7 @@ import net.ess3.api.events.JailStatusChangeEvent;
 import net.ess3.api.events.MuteStatusChangeEvent;
 import net.ess3.api.events.UserBalanceUpdateEvent;
 import net.essentialsx.api.v2.events.TransactionEvent;
+import net.essentialsx.api.v2.services.mail.MailSender;
 import org.bukkit.Location;
 import org.bukkit.Material;
 import org.bukkit.Statistic;
@@ -987,6 +988,11 @@ public class User extends UserData implements Comparable<User>, IMessageRecipien
         return this.getBase().getName();
     }
 
+    @Override
+    public UUID getUUID() {
+        return getBase().getUniqueId();
+    }
+
     @Override
     public boolean isReachable() {
         return getBase().isOnline();
@@ -1054,12 +1060,28 @@ public class User extends UserData implements Comparable<User>, IMessageRecipien
         }
     }
 
+    @Override
+    public void sendMail(MailSender sender, String message) {
+        sendMail(sender, message, 0);
+    }
+
+    @Override
+    public void sendMail(MailSender sender, String message, long expireAt) {
+        ess.getMail().sendMail(this, sender, message, expireAt);
+    }
+
+    @Override
+    @Deprecated
+    public void addMail(String mail) {
+        ess.getMail().sendLegacyMail(this, mail);
+    }
+
     public void notifyOfMail() {
-        final List<String> mails = getMails();
+        final int unread = getUnreadMailAmount();
-        if (mails != null && !mails.isEmpty()) {
+        if (unread != 0) {
             final int notifyPlayerOfMailCooldown = ess.getSettings().getNotifyPlayerOfMailCooldown() * 1000;
             if (System.currentTimeMillis() - lastNotifiedAboutMailsMs >= notifyPlayerOfMailCooldown) {
-                sendMessage(tl("youHaveNewMail", mails.size()));
+                sendMessage(tl("youHaveNewMail", unread));
                 lastNotifiedAboutMailsMs = System.currentTimeMillis();
             }
         }

Essentials/src/main/java/com/earth2me/essentials/UserData.java

@@ -10,6 +10,8 @@ import com.earth2me.essentials.utils.StringUtil;
 import com.google.common.base.Charsets;
 import net.ess3.api.IEssentials;
 import net.ess3.api.MaxMoneyException;
+import net.essentialsx.api.v2.services.mail.MailMessage;
+import org.bukkit.ChatColor;
 import org.bukkit.Location;
 import org.bukkit.Material;
 import org.bukkit.entity.Player;
@@ -313,17 +315,59 @@ public abstract class UserData extends PlayerExtension implements IConf {
         config.save();
     }
 
+    /**
+     * @deprecated Mails are no longer just strings, this method is therefore misleading.
+     */
+    @Deprecated
     public List<String> getMails() {
-        return holder.mail();
+        final List<String> list = new ArrayList<>();
+        if (getMailAmount() != 0) {
+            for (MailMessage mail : getMailMessages()) {
+                // I hate this code btw
+                list.add(mail.isLegacy() ? mail.getMessage() : ChatColor.GOLD + "[" + ChatColor.RESET + mail.getSenderUsername() + ChatColor.GOLD + "] " + ChatColor.RESET + mail.getMessage());
+            }
+        }
+        return list;
     }
 
+    /**
+     * @deprecated This method does not support the new mail system and will fail at runtime.
+     */
+    @Deprecated
     public void setMails(List<String> mails) {
-        holder.mail(mails);
+        throw new UnsupportedOperationException("UserData#setMails(List<String>) is deprecated and can no longer be used. Please tell the plugin author to update this!");
-        config.save();
     }
 
-    public void addMail(final String mail) {
+    public int getMailAmount() {
-        holder.mail().add(mail);
+        return holder.mail() == null ? 0 : holder.mail().size();
+    }
+
+    public int getUnreadMailAmount() {
+        if (holder.mail() == null || holder.mail().isEmpty()) {
+            return 0;
+        }
+
+        int unread = 0;
+        for (MailMessage element : holder.mail()) {
+            if (!element.isRead()) {
+                unread++;
+            }
+        }
+        return unread;
+    }
+
+    /**
+     * @deprecated This method does not support the new mail system and should not be used.
+     */
+    @Deprecated
+    abstract void addMail(final String mail);
+
+    public ArrayList<MailMessage> getMailMessages() {
+        return new ArrayList<>(holder.mail());
+    }
+
+    public void setMailList(ArrayList<MailMessage> messages) {
+        holder.mail(messages);
         config.save();
     }
 

Essentials/src/main/java/com/earth2me/essentials/commands/Commandmail.java

@@ -1,18 +1,23 @@
 package com.earth2me.essentials.commands;
 
 import com.earth2me.essentials.CommandSource;
+import com.earth2me.essentials.Console;
 import com.earth2me.essentials.User;
-import com.earth2me.essentials.textreader.IText;
+import com.earth2me.essentials.messaging.IMessageRecipient;
 import com.earth2me.essentials.textreader.SimpleTextInput;
 import com.earth2me.essentials.textreader.TextPager;
 import com.earth2me.essentials.utils.DateUtil;
 import com.earth2me.essentials.utils.FormatUtil;
+import com.earth2me.essentials.utils.NumberUtil;
 import com.earth2me.essentials.utils.StringUtil;
 import com.google.common.collect.Lists;
+import net.essentialsx.api.v2.services.mail.MailMessage;
 import org.bukkit.Server;
 
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import java.util.ListIterator;
 import java.util.UUID;
 
 import static com.earth2me.essentials.I18n.tl;
@@ -28,17 +33,35 @@ public class Commandmail extends EssentialsCommand {
     @Override
     public void run(final Server server, final User user, final String commandLabel, final String[] args) throws Exception {
         if (args.length >= 1 && "read".equalsIgnoreCase(args[0])) {
-            final List<String> mail = user.getMails();
+            final ArrayList<MailMessage> mail = user.getMailMessages();
-            if (mail.isEmpty()) {
+            if (mail == null || mail.size() == 0) {
+                user.sendMessage(tl("noMail"));
+                throw new NoChargeException();
+            }
+
+            final SimpleTextInput input = new SimpleTextInput();
+            final ListIterator<MailMessage> iterator = mail.listIterator();
+            while (iterator.hasNext()) {
+                final MailMessage mailObj = iterator.next();
+                if (mailObj.isExpired()) {
+                    iterator.remove();
+                    continue;
+                }
+                input.addLine(ess.getMail().getMailLine(mailObj));
+                iterator.set(new MailMessage(true, mailObj.isLegacy(), mailObj.getSenderUsername(),
+                        mailObj.getSenderUUID(), mailObj.getTimeSent(), mailObj.getTimeExpire(), mailObj.getMessage()));
+            }
+
+            if (input.getLines().isEmpty()) {
                 user.sendMessage(tl("noMail"));
                 throw new NoChargeException();
             }
 
-            final IText input = new SimpleTextInput(mail);
             final TextPager pager = new TextPager(input);
             pager.showPage(args.length > 1 ? args[1] : null, null, commandLabel + " " + args[0], user.getSource());
 
             user.sendMessage(tl("mailClear"));
+            user.setMailList(mail);
             return;
         }
         if (args.length >= 3 && "send".equalsIgnoreCase(args[0])) {
@@ -61,8 +84,8 @@ public class Commandmail extends EssentialsCommand {
                 throw new Exception(tl("playerNeverOnServer", args[1]));
             }
 
-            final String mail = tl("mailFormat", user.getName(), FormatUtil.formatMessage(user, "essentials.mail", StringUtil.sanitizeString(FormatUtil.stripFormat(getFinalArg(args, 2)))));
+            final String msg = FormatUtil.formatMessage(user, "essentials.mail", StringUtil.sanitizeString(FormatUtil.stripFormat(getFinalArg(args, 2))));
-            if (mail.length() > 1000) {
+            if (msg.length() > 1000) {
                 throw new Exception(tl("mailTooLong"));
             }
 
@@ -75,29 +98,87 @@ public class Commandmail extends EssentialsCommand {
                 if (mailsPerMinute > ess.getSettings().getMailsPerMinute()) {
                     throw new Exception(tl("mailDelay", ess.getSettings().getMailsPerMinute()));
                 }
-                u.addMail(tl("mailMessage", mail));
+                u.sendMail(user, msg);
             }
 
             user.sendMessage(tl("mailSentTo", u.getDisplayName(), u.getName()));
-            user.sendMessage(mail);
+            user.sendMessage(msg);
+            return;
+        }
+        if (args.length >= 4 && "sendtemp".equalsIgnoreCase(args[0])) {
+            if (!user.isAuthorized("essentials.mail.sendtemp")) {
+                throw new Exception(tl("noPerm", "essentials.mail.sendtemp"));
+            }
+
+            if (user.isMuted()) {
+                final String dateDiff = user.getMuteTimeout() > 0 ? DateUtil.formatDateDiff(user.getMuteTimeout()) : null;
+                if (dateDiff == null) {
+                    throw new Exception(user.hasMuteReason() ? tl("voiceSilencedReason", user.getMuteReason()) : tl("voiceSilenced"));
+                }
+                throw new Exception(user.hasMuteReason() ? tl("voiceSilencedReasonTime", dateDiff, user.getMuteReason()) : tl("voiceSilencedTime", dateDiff));
+            }
+
+            final User u;
+            try {
+                u = getPlayer(server, args[1], true, true);
+            } catch (final PlayerNotFoundException e) {
+                throw new Exception(tl("playerNeverOnServer", args[1]));
+            }
+
+            final long dateDiff = DateUtil.parseDateDiff(args[2], true);
+
+            final String msg = FormatUtil.formatMessage(user, "essentials.mail", StringUtil.sanitizeString(FormatUtil.stripFormat(getFinalArg(args, 3))));
+            if (msg.length() > 1000) {
+                throw new Exception(tl("mailTooLong"));
+            }
+
+            if (!u.isIgnoredPlayer(user)) {
+                if (Math.abs(System.currentTimeMillis() - timestamp) > 60000) {
+                    timestamp = System.currentTimeMillis();
+                    mailsPerMinute = 0;
+                }
+                mailsPerMinute++;
+                if (mailsPerMinute > ess.getSettings().getMailsPerMinute()) {
+                    throw new Exception(tl("mailDelay", ess.getSettings().getMailsPerMinute()));
+                }
+                u.sendMail(user, msg, dateDiff);
+            }
+
+            user.sendMessage(tl("mailSentToExpire", u.getDisplayName(), DateUtil.formatDateDiff(dateDiff), u.getName()));
+            user.sendMessage(msg);
             return;
         }
         if (args.length > 1 && "sendall".equalsIgnoreCase(args[0])) {
             if (!user.isAuthorized("essentials.mail.sendall")) {
                 throw new Exception(tl("noPerm", "essentials.mail.sendall"));
             }
-            ess.runTaskAsynchronously(new SendAll(tl("mailFormat", user.getName(),
+            ess.runTaskAsynchronously(new SendAll(user, FormatUtil.formatMessage(user, "essentials.mail", StringUtil.sanitizeString(FormatUtil.stripFormat(getFinalArg(args, 1))))));
-                FormatUtil.formatMessage(user, "essentials.mail", StringUtil.sanitizeString(FormatUtil.stripFormat(getFinalArg(args, 1)))))));
             user.sendMessage(tl("mailSent"));
             return;
         }
         if (args.length >= 1 && "clear".equalsIgnoreCase(args[0])) {
-            if (user.getMails() == null || user.getMails().isEmpty()) {
+            final ArrayList<MailMessage> mails = user.getMailMessages();
+            if (mails == null || mails.size() == 0) {
                 user.sendMessage(tl("noMail"));
                 throw new NoChargeException();
             }
 
-            user.setMails(null);
+            if (args.length > 1) {
+                if (!NumberUtil.isPositiveInt(args[1])) {
+                    throw new NotEnoughArgumentsException();
+                }
+
+                final int toRemove = Integer.parseInt(args[1]);
+                if (toRemove > mails.size()) {
+                    user.sendMessage(tl("mailClearIndex", mails.size()));
+                    return;
+                }
+                mails.remove(toRemove - 1);
+                user.setMailList(mails);
+            } else {
+                user.setMailList(null);
+            }
+
             user.sendMessage(tl("mailCleared"));
             return;
         }
@@ -117,11 +198,22 @@ public class Commandmail extends EssentialsCommand {
             } catch (final PlayerNotFoundException e) {
                 throw new Exception(tl("playerNeverOnServer", args[1]));
             }
-            u.addMail(tl("mailFormat", "Server", FormatUtil.replaceFormat(getFinalArg(args, 2))));
+            u.sendMail(Console.getInstance(), FormatUtil.replaceFormat(getFinalArg(args, 2)));
+            sender.sendMessage(tl("mailSent"));
+            return;
+        } else if (args.length >= 4 && "sendtemp".equalsIgnoreCase(args[0])) {
+            final User u;
+            try {
+                u = getPlayer(server, args[1], true, true);
+            } catch (final PlayerNotFoundException e) {
+                throw new Exception(tl("playerNeverOnServer", args[1]));
+            }
+            final long dateDiff = DateUtil.parseDateDiff(args[2], true);
+            u.sendMail(Console.getInstance(), FormatUtil.replaceFormat(getFinalArg(args, 3)), dateDiff);
             sender.sendMessage(tl("mailSent"));
             return;
         } else if (args.length >= 2 && "sendall".equalsIgnoreCase(args[0])) {
-            ess.runTaskAsynchronously(new SendAll(tl("mailFormat", "Server", FormatUtil.replaceFormat(getFinalArg(args, 1)))));
+            ess.runTaskAsynchronously(new SendAll(Console.getInstance(), FormatUtil.replaceFormat(getFinalArg(args, 1))));
             sender.sendMessage(tl("mailSent"));
             return;
         } else if (args.length >= 2) {
@@ -132,13 +224,33 @@ public class Commandmail extends EssentialsCommand {
             } catch (final PlayerNotFoundException e) {
                 throw new Exception(tl("playerNeverOnServer", args[0]));
             }
-            u.addMail(tl("mailFormat", "Server", FormatUtil.replaceFormat(getFinalArg(args, 1))));
+            u.sendMail(Console.getInstance(), FormatUtil.replaceFormat(getFinalArg(args, 1)));
             sender.sendMessage(tl("mailSent"));
             return;
         }
         throw new NotEnoughArgumentsException();
     }
 
+    private class SendAll implements Runnable {
+        IMessageRecipient messageRecipient;
+        String message;
+
+        SendAll(IMessageRecipient messageRecipient, String message) {
+            this.messageRecipient = messageRecipient;
+            this.message = message;
+        }
+
+        @Override
+        public void run() {
+            for (UUID userid : ess.getUserMap().getAllUniqueUsers()) {
+                final User user = ess.getUserMap().getUser(userid);
+                if (user != null) {
+                    user.sendMail(messageRecipient, message);
+                }
+            }
+        }
+    }
+
     @Override
     protected List<String> getTabCompleteOptions(final Server server, final User user, final String commandLabel, final String[] args) {
         if (args.length == 1) {
@@ -146,15 +258,18 @@ public class Commandmail extends EssentialsCommand {
             if (user.isAuthorized("essentials.mail.send")) {
                 options.add("send");
             }
+            if (user.isAuthorized("essentials.mail.sendtemp")) {
+                options.add("sendtemp");
+            }
             if (user.isAuthorized("essentials.mail.sendall")) {
                 options.add("sendall");
             }
             return options;
-        } else if (args.length == 2 && args[0].equalsIgnoreCase("send") && user.isAuthorized("essentials.mail.send")) {
+        } else if (args.length == 2 && ((args[0].equalsIgnoreCase("send") && user.isAuthorized("essentials.mail.send")) || (args[0].equalsIgnoreCase("sendtemp") && user.isAuthorized("essentials.mail.sendtemp")))) {
             return getPlayers(server, user);
         } else if (args.length == 2 && args[0].equalsIgnoreCase("read")) {
-            final List<String> mail = user.getMails();
+            final ArrayList<MailMessage> mail = user.getMailMessages();
-            final int pages = mail.size() / 9 + (mail.size() % 9 > 0 ? 1 : 0);
+            final int pages = mail != null ? (mail.size() / 9 + (mail.size() % 9 > 0 ? 1 : 0)) : 0;
             if (pages == 0) {
                 return Lists.newArrayList("0");
             } else {
@@ -164,8 +279,8 @@ public class Commandmail extends EssentialsCommand {
                 }
                 return options;
             }
-        } else if ((args.length > 2 && args[0].equalsIgnoreCase("send") && user.isAuthorized("essentials.mail.send")) || (args.length > 1 && args[0].equalsIgnoreCase("sendall") && user.isAuthorized("essentials.mail.sendall"))) {
+        } else if (args.length == 3 && args[0].equalsIgnoreCase("sendtemp") && user.isAuthorized("essentials.mail.sendtemp")) {
-            return null; // Use vanilla handler
+            return COMMON_DATE_DIFFS;
         } else {
             return Collections.emptyList();
         }
@@ -175,30 +290,14 @@ public class Commandmail extends EssentialsCommand {
     protected List<String> getTabCompleteOptions(final Server server, final CommandSource sender, final String commandLabel, final String[] args) {
         if (args.length == 1) {
             return Lists.newArrayList("send", "sendall");
-        } else if (args.length == 2 && args[0].equalsIgnoreCase("send")) {
+        } else if (args.length == 2 && (args[0].equalsIgnoreCase("send") || args[0].equalsIgnoreCase("sendtemp"))) {
             return getPlayers(server, sender);
+        } else if (args.length == 3 && args[0].equalsIgnoreCase("sentemp")) {
+            return COMMON_DATE_DIFFS;
         } else if ((args.length > 2 && args[0].equalsIgnoreCase("send")) || (args.length > 1 && args[0].equalsIgnoreCase("sendall"))) {
             return null; // Use vanilla handler
         } else {
             return Collections.emptyList();
         }
     }
-
-    private class SendAll implements Runnable {
-        final String message;
-
-        SendAll(final String message) {
-            this.message = message;
-        }
-
-        @Override
-        public void run() {
-            for (final UUID userid : ess.getUserMap().getAllUniqueUsers()) {
-                final User user = ess.getUserMap().getUser(userid);
-                if (user != null) {
-                    user.addMail(message);
-                }
-            }
-        }
-    }
 }

Essentials/src/main/java/com/earth2me/essentials/config/EssentialsConfiguration.java

@@ -9,8 +9,10 @@ import com.earth2me.essentials.config.processors.DeleteOnEmptyProcessor;
 import com.earth2me.essentials.config.serializers.BigDecimalTypeSerializer;
 import com.earth2me.essentials.config.serializers.CommandCooldownSerializer;
 import com.earth2me.essentials.config.serializers.LocationTypeSerializer;
+import com.earth2me.essentials.config.serializers.MailMessageSerializer;
 import com.earth2me.essentials.config.serializers.MaterialTypeSerializer;
 import net.ess3.api.InvalidWorldException;
+import net.essentialsx.api.v2.services.mail.MailMessage;
 import org.bukkit.Location;
 import org.bukkit.Material;
 import org.spongepowered.configurate.CommentedConfigurationNode;
@@ -26,6 +28,7 @@ import org.spongepowered.configurate.yaml.YamlConfigurationLoader;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
+import java.lang.reflect.Type;
 import java.math.BigDecimal;
 import java.nio.file.Files;
 import java.util.ArrayList;
@@ -58,6 +61,7 @@ public class EssentialsConfiguration {
             .register(LazyLocation.class, new LocationTypeSerializer())
             .register(Material.class, new MaterialTypeSerializer())
             .register(CommandCooldown.class, new CommandCooldownSerializer())
+            .register(MailMessage.class, new MailMessageSerializer())
             .build();
 
     private final AtomicInteger pendingWrites = new AtomicInteger(0);
@@ -139,6 +143,14 @@ public class EssentialsConfiguration {
         setInternal(path, list);
     }
 
+    public <T> void setExplicitList(final String path, final List<T> list, final Type type) {
+        try {
+            toSplitRoot(path, configurationNode).set(type, list);
+        } catch (SerializationException e) {
+            LOGGER.log(Level.SEVERE, e.getMessage(), e);
+        }
+    }
+
     public <T> List<T> getList(final String path, Class<T> type) {
         final CommentedConfigurationNode node = getInternal(path);
         if (node == null) {

Essentials/src/main/java/com/earth2me/essentials/config/holders/UserConfigHolder.java

@@ -4,6 +4,7 @@ import com.earth2me.essentials.config.annotations.DeleteIfIncomplete;
 import com.earth2me.essentials.config.annotations.DeleteOnEmpty;
 import com.earth2me.essentials.config.entities.CommandCooldown;
 import com.earth2me.essentials.config.entities.LazyLocation;
+import net.essentialsx.api.v2.services.mail.MailMessage;
 import org.bukkit.Location;
 import org.bukkit.Material;
 import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
@@ -113,16 +114,16 @@ public class UserConfigHolder {
     }
 
     @DeleteOnEmpty
-    private @MonotonicNonNull List<String> mail;
+    private @MonotonicNonNull ArrayList<MailMessage> mail;
 
-    public List<String> mail() {
+    public ArrayList<MailMessage> mail() {
         if (this.mail == null) {
             this.mail = new ArrayList<>();
         }
         return this.mail;
     }
 
-    public void mail(final List<String> value) {
+    public void mail(final ArrayList<MailMessage> value) {
         this.mail = value;
     }
 

Essentials/src/main/java/com/earth2me/essentials/config/serializers/MailMessageSerializer.java

@@ -0,0 +1,44 @@
+package com.earth2me.essentials.config.serializers;
+
+import net.essentialsx.api.v2.services.mail.MailMessage;
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.spongepowered.configurate.ConfigurationNode;
+import org.spongepowered.configurate.serialize.SerializationException;
+import org.spongepowered.configurate.serialize.TypeSerializer;
+
+import java.lang.reflect.Type;
+import java.util.Objects;
+import java.util.UUID;
+
+public class MailMessageSerializer implements TypeSerializer<MailMessage> {
+    @Override
+    public MailMessage deserialize(Type type, ConfigurationNode node) throws SerializationException {
+        final boolean legacy = !node.node("legacy").isNull() && node.node("legacy").getBoolean(false);
+
+        return new MailMessage(node.node("read").getBoolean(false),
+                legacy,
+                !legacy ? node.node("sender-name").getString() : null,
+                !legacy ? UUID.fromString(Objects.requireNonNull(node.node("sender-uuid").getString())) : null,
+                !legacy ? node.node("timestamp").getLong() : 0L,
+                !legacy ? node.node("expire").getLong() : 0L,
+                node.node("message").getString());
+    }
+
+    @Override
+    public void serialize(Type type, @Nullable MailMessage obj, ConfigurationNode node) throws SerializationException {
+        if (obj == null) {
+            node.raw(null);
+            return;
+        }
+
+        node.node("legacy").set(Boolean.class, obj.isLegacy());
+        node.node("read").set(Boolean.class, obj.isRead());
+        node.node("message").set(String.class, obj.getMessage());
+        if (!obj.isLegacy()) {
+            node.node("sender-name").set(String.class, obj.getSenderUsername());
+            node.node("sender-uuid").set(String.class, obj.getSenderUUID().toString());
+            node.node("timestamp").set(Long.class, obj.getTimeSent());
+            node.node("expire").set(Long.class, obj.getTimeExpire());
+        }
+    }
+}

Essentials/src/main/java/com/earth2me/essentials/messaging/IMessageRecipient.java

@@ -1,11 +1,12 @@
 package com.earth2me.essentials.messaging;
 
+import net.essentialsx.api.v2.services.mail.MailSender;
 import org.bukkit.entity.Player;
 
 /**
  * Represents an interface for message recipients.
  */
-public interface IMessageRecipient {
+public interface IMessageRecipient extends MailSender {
 
     /**
      * Sends (prints) a message to this recipient.

Essentials/src/main/java/com/earth2me/essentials/messaging/SimpleMessageRecipient.java

@@ -8,6 +8,7 @@ import net.ess3.api.events.PrivateMessageSentEvent;
 import org.bukkit.entity.Player;
 
 import java.lang.ref.WeakReference;
+import java.util.UUID;
 
 import static com.earth2me.essentials.I18n.tl;
 
@@ -60,6 +61,11 @@ public class SimpleMessageRecipient implements IMessageRecipient {
         return this.parent.getName();
     }
 
+    @Override
+    public UUID getUUID() {
+        return this.parent.getUUID();
+    }
+
     @Override
     public String getDisplayName() {
         return this.parent.getDisplayName();

Essentials/src/main/java/com/earth2me/essentials/signs/SignMail.java

@@ -2,8 +2,10 @@ package com.earth2me.essentials.signs;
 
 import com.earth2me.essentials.User;
 import net.ess3.api.IEssentials;
+import net.essentialsx.api.v2.services.mail.MailMessage;
 
-import java.util.List;
+import java.util.ArrayList;
+import java.util.ListIterator;
 
 import static com.earth2me.essentials.I18n.tl;
 
@@ -14,14 +16,28 @@ public class SignMail extends EssentialsSign {
 
     @Override
     protected boolean onSignInteract(final ISign sign, final User player, final String username, final IEssentials ess) throws SignException {
-        final List<String> mail = player.getMails();
+        final ArrayList<MailMessage> mail = player.getMailMessages();
-        if (mail.isEmpty()) {
+
+        final ListIterator<MailMessage> iterator = mail.listIterator();
+        boolean hadMail = false;
+        while (iterator.hasNext()) {
+            final MailMessage mailObj = iterator.next();
+            if (mailObj.isExpired()) {
+                iterator.remove();
+                continue;
+            }
+            hadMail = true;
+            player.sendMessage(ess.getMail().getMailLine(mailObj));
+            iterator.set(new MailMessage(true, mailObj.isLegacy(), mailObj.getSenderUsername(),
+                    mailObj.getSenderUUID(), mailObj.getTimeSent(), mailObj.getTimeExpire(), mailObj.getMessage()));
+        }
+
+        if (!hadMail) {
             player.sendMessage(tl("noNewMail"));
             return false;
         }
-        for (final String s : mail) {
+        player.setMailList(mail);
-            player.sendMessage(s);
+
-        }
         player.sendMessage(tl("markMailAsRead"));
         return true;
     }

Essentials/src/main/java/com/earth2me/essentials/textreader/KeywordReplacer.java

@@ -227,7 +227,7 @@ public class KeywordReplacer implements IText {
                         break;
                     case MAILS:
                         if (user != null) {
-                            replacer = Integer.toString(user.getMails().size());
+                            replacer = Integer.toString(user.getMailAmount());
                         }
                         break;
                     case PLAYTIME:

Essentials/src/main/java/com/earth2me/essentials/textreader/SimpleTextInput.java

@@ -20,6 +20,10 @@ public class SimpleTextInput implements IText {
     public SimpleTextInput() {
     }
 
+    public void addLine(String line) {
+        lines.add(line);
+    }
+
     @Override
     public List<String> getLines() {
         return lines;

Essentials/src/main/java/net/essentialsx/api/v2/services/mail/MailMessage.java

@@ -0,0 +1,98 @@
+package net.essentialsx.api.v2.services.mail;
+
+import java.util.UUID;
+
+/**
+ * An immutable representation of a message sent as mail.
+ */
+public class MailMessage {
+    private final boolean read;
+    private final boolean legacy;
+    private final String senderName;
+    private final UUID senderId;
+    private final long timestamp;
+    private final long expire;
+    private final String message;
+
+    public MailMessage(boolean read, boolean legacy, String sender, UUID uuid, long timestamp, long expire, String message) {
+        this.read = read;
+        this.legacy = legacy;
+        this.senderName = sender;
+        this.senderId = uuid;
+        this.timestamp = timestamp;
+        this.expire = expire;
+        this.message = message;
+    }
+
+    /**
+     * Checks if this message has been read by its recipient yet.
+     * @return true if this message has been read.
+     */
+    public boolean isRead() {
+        return read;
+    }
+
+    /**
+     * Checks if this message was created via legacy api or converted from legacy format.
+     *
+     * A legacy messages only contains data for the read state and message.
+     * @see #isRead()
+     * @see #getMessage()
+     * @return true if this message is a legacy message.
+     */
+    public boolean isLegacy() {
+        return legacy;
+    }
+
+    /**
+     * Gets the sender's username at the time of sending the message.
+     * @return The sender's username.
+     */
+    public String getSenderUsername() {
+        return senderName;
+    }
+
+    /**
+     * Gets the sender's {@link UUID} or null if the sender does not have a UUID.
+     * @return The sender's {@link UUID} or null.
+     */
+    public UUID getSenderUUID() {
+        return senderId;
+    }
+
+    /**
+     * Gets the millisecond epoch time when the message was sent.
+     * @return The epoch time when message was sent.
+     */
+    public long getTimeSent() {
+        return timestamp;
+    }
+
+    /**
+     * Gets the millisecond epoch at which this message will expire and no longer been shown to the user.
+     * @return The epoch time when the message will expire.
+     */
+    public long getTimeExpire() {
+        return expire;
+    }
+
+    /**
+     * Gets the message content for normal mail or the entire mail format for legacy mail.
+     * @see #isLegacy()
+     * @return The mail content or format.
+     */
+    public String getMessage() {
+        return message;
+    }
+
+    /**
+     * Helper method to check if this mail has expired and should not been shown to the recipient.
+     * @return true if this mail has expired.
+     */
+    public boolean isExpired() {
+        if (getTimeExpire() == 0L) {
+            return false;
+        }
+        return System.currentTimeMillis() >= getTimeExpire();
+    }
+}

Essentials/src/main/java/net/essentialsx/api/v2/services/mail/MailSender.java

@@ -0,0 +1,22 @@
+package net.essentialsx.api.v2.services.mail;
+
+import java.util.UUID;
+
+/**
+ * An entity which is allowed to send mail to an {@link net.ess3.api.IUser IUser}.
+ *
+ * In Essentials, IUser and Console are the entities that implement this interface.
+ */
+public interface MailSender {
+    /**
+     * Gets the username of this {@link MailSender}.
+     * @return The sender's username.
+     */
+    String getName();
+
+    /**
+     * Gets the {@link UUID} of this {@link MailSender} or null if this sender doesn't have a UUID.
+     * @return The sender's {@link UUID} or null if N/A.
+     */
+    UUID getUUID();
+}

Essentials/src/main/java/net/essentialsx/api/v2/services/mail/MailService.java

@@ -0,0 +1,43 @@
+package net.essentialsx.api.v2.services.mail;
+
+import net.ess3.api.IUser;
+
+/**
+ * This interface provides access to core Essentials mailing functions, allowing API users to send messages to {@link IUser IUser's }.
+ */
+public interface MailService {
+    /**
+     * Sends a message from the specified {@link MailSender sender} to the specified {@link IUser recipient}.
+     * @param recipient The {@link IUser} which to send the message to.
+     * @param sender    The {@link MailSender} which sent the message.
+     * @param message   The message content.
+     */
+    void sendMail(IUser recipient, MailSender sender, String message);
+
+    /**
+     * Sends a message from the specified {@link MailSender sender} to the specified {@link IUser recipient}.
+     * @param recipient The {@link IUser} which to send the message to.
+     * @param sender    The {@link MailSender} which sent the message.
+     * @param message   The message content.
+     * @param expireAt  The millisecond epoch at which this message expires, or 0 if the message doesn't expire.
+     */
+    void sendMail(IUser recipient, MailSender sender, String message, long expireAt);
+
+    /**
+     * Sends a legacy message to the user without any advanced features.
+     * @param recipient The {@link IUser} which to send the message to.
+     * @param message   The message content.
+     * @see #sendMail(IUser, MailSender, String)
+     * @see #sendMail(IUser, MailSender, String, long)
+     * @deprecated This is only for maintaining backwards compatibility with old API, please use the newer {@link #sendMail(IUser, MailSender, String)} API.
+     */
+    @Deprecated
+    void sendLegacyMail(IUser recipient, String message);
+
+    /**
+     * Generates the message sent to the recipient of the given {@link MailMessage}.
+     * @param message The {@link MailMessage} to generate the message for.
+     * @return The formatted message to be sent to the recipient.
+     */
+    String getMailLine(MailMessage message);
+}

Essentials/src/main/resources/messages.properties

@@ -647,21 +647,29 @@ loomCommandDescription=Opens up a loom.
 loomCommandUsage=/<command>
 mailClear=\u00a76To clear your mail, type\u00a7c /mail clear\u00a76.
 mailCleared=\u00a76Mail cleared\!
+mailClearIndex=\u00a74You must specify a number between 1-{0}.
 mailCommandDescription=Manages inter-player, intra-server mail.
-mailCommandUsage=/<command> [read|clear|send [to] [message]|sendall [message]]
+mailCommandUsage=/<command> [read|clear|clear [number]|send [to] [message]|sendtemp [to] [expire time] [message]|sendall [message]]
 mailCommandUsage1=/<command> read [page]
 mailCommandUsage1Description=Reads the first (or specified) page of your mail
-mailCommandUsage2=/<command> clear
+mailCommandUsage2=/<command> clear [number]
-mailCommandUsage2Description=Clears your mail
+mailCommandUsage2Description=Clears either all or the specified mail(s)
 mailCommandUsage3=/<command> send <player> <message>
 mailCommandUsage3Description=Sends the specified player the given message
 mailCommandUsage4=/<command> sendall <message>
 mailCommandUsage4Description=Sends all players the given message
+mailCommandUsage5=/<command> sendtemp <player> <expire time> <message>
+mailCommandUsage5Description=Sends the specified player the given message which will expire in the specified time
 mailDelay=Too many mails have been sent within the last minute. Maximum\: {0}
+mailFormatNew=\u00a76[\u00a7r{0}\u00a76] \u00a76[\u00a7r{1}\u00a76] \u00a7r{2}
+mailFormatNewTimed=\u00a76[\u00a7e\u26a0\u00a76] \u00a76[\u00a7r{0}\u00a76] \u00a76[\u00a7r{1}\u00a76] \u00a7r{2}
+mailFormatNewRead=\u00a76[\u00a7r{0}\u00a76] \u00a76[\u00a7r{1}\u00a76] \u00a77\u00a7o{2}
+mailFormatNewReadTimed=\u00a76[\u00a7e\u26a0\u00a76] \u00a76[\u00a7r{0}\u00a76] \u00a76[\u00a7r{1}\u00a76] \u00a77\u00a7o{2}
 mailFormat=\u00a76[\u00a7r{0}\u00a76] \u00a7r{1}
 mailMessage={0}
 mailSent=\u00a76Mail sent\!
 mailSentTo=\u00a7c{0}\u00a76 has been sent the following mail\:
+mailSentToExpire=\u00a7c{0}\u00a76 has been sent the following mail which will expire in \u00a7c{1}\u00a76\:
 mailTooLong=\u00a74Mail message too long. Try to keep it below 1000 characters.
 markMailAsRead=\u00a76To mark your mail as read, type\u00a7c /mail clear\u00a76.
 matchingIPAddress=\u00a76The following players previously logged in from that IP address\:

Essentials/src/main/resources/plugin.yml

@@ -286,7 +286,7 @@ commands:
     aliases: [eloom]
   mail:
     description: Manages inter-player, intra-server mail.
-    usage: /<command> [read|clear|send [to] [message]|sendall [message]]
+    usage: /<command> [read|clear|clear [number]|send [to] [message]|sendtemp [to] [expire time] [message]|sendall [message]]
     aliases: [email,eemail,memo,ememo]
   me:
     description: Describes an action in the context of the player.

EssentialsDiscord/src/main/java/net/essentialsx/discord/util/DiscordMessageRecipient.java

@@ -5,6 +5,7 @@ import com.earth2me.essentials.utils.FormatUtil;
 import net.essentialsx.api.v2.services.discord.InteractionMember;
 import org.bukkit.entity.Player;
 
+import java.util.UUID;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import static com.earth2me.essentials.I18n.tl;
@@ -48,6 +49,11 @@ public class DiscordMessageRecipient implements IMessageRecipient {
         return member.getTag();
     }
 
+    @Override
+    public UUID getUUID() {
+        return null;
+    }
+
     @Override
     public String getDisplayName() {
         return member.getTag();