diff --git a/dao/register.go b/dao/register.go
index 95798b3802..6f5351504b 100644
--- a/dao/register.go
+++ b/dao/register.go
@@ -17,7 +17,7 @@ package dao
 
 import (
 	"errors"
-	//	"regexp"
+	"regexp"
 	"time"
 
 	"github.com/vmware/harbor/models"
@@ -74,8 +74,13 @@ func validate(user models.User) error {
 		return errors.New("Username already exists.")
 	}
 
-	if exist, _ := UserExists(models.User{Email: user.Email}, "email"); len(user.Email) > 0 && exist {
-		return errors.New("Email already exists.")
+	if len(user.Email) > 0 {
+		if m, _ := regexp.MatchString(`^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$`, user.Email); !m {
+			return errors.New("Email with illegal format.")
+		}
+		if exist, _ := UserExists(models.User{Email: user.Email}, "email"); exist {
+			return errors.New("Email already exists.")
+		}
 	}
 
 	if isIllegalLength(user.Realname, 0, 20) {