diff --git a/routers/private/mail.go b/routers/private/mail.go
index 8b69c3809..853b58b09 100644
--- a/routers/private/mail.go
+++ b/routers/private/mail.go
@@ -60,7 +60,7 @@ func SendEmail(ctx *context.PrivateContext) {
 		}
 	} else {
 		err := user_model.IterateUser(func(user *user_model.User) error {
-			if len(user.Email) > 0 {
+			if len(user.Email) > 0 && user.IsActive {
 				emails = append(emails, user.Email)
 			}
 			return nil
diff --git a/services/mailer/mail.go b/services/mailer/mail.go
index 3d93f1bd6..e0a454d49 100644
--- a/services/mailer/mail.go
+++ b/services/mailer/mail.go
@@ -146,8 +146,8 @@ func SendActivateEmailMail(u *user_model.User, email *user_model.EmailAddress) {
 
 // SendRegisterNotifyMail triggers a notify e-mail by admin created a account.
 func SendRegisterNotifyMail(u *user_model.User) {
-	if setting.MailService == nil {
-		// No mail service configured
+	if setting.MailService == nil || !u.IsActive {
+		// No mail service configured OR user is inactive
 		return
 	}
 	locale := translation.NewLocale(u.Language)
@@ -176,8 +176,8 @@ func SendRegisterNotifyMail(u *user_model.User) {
 
 // SendCollaboratorMail sends mail notification to new collaborator.
 func SendCollaboratorMail(u, doer *user_model.User, repo *repo_model.Repository) {
-	if setting.MailService == nil {
-		// No mail service configured
+	if setting.MailService == nil || !u.IsActive {
+		// No mail service configured OR the user is inactive
 		return
 	}
 	locale := translation.NewLocale(u.Language)
@@ -404,6 +404,10 @@ func SendIssueAssignedMail(issue *models.Issue, doer *user_model.User, content s
 
 	langMap := make(map[string][]*user_model.User)
 	for _, user := range recipients {
+		if !user.IsActive {
+			// don't send emails to inactive users
+			continue
+		}
 		langMap[user.Language] = append(langMap[user.Language], user)
 	}
 
diff --git a/services/mailer/mail_issue.go b/services/mailer/mail_issue.go
index c9cc2e015..c37414df0 100644
--- a/services/mailer/mail_issue.go
+++ b/services/mailer/mail_issue.go
@@ -125,6 +125,10 @@ func mailIssueCommentBatch(ctx *mailCommentContext, users []*user_model.User, vi
 
 	langMap := make(map[string][]*user_model.User)
 	for _, user := range users {
+		if !user.IsActive {
+			// Exclude deactivated users
+			continue
+		}
 		// At this point we exclude:
 		// user that don't have all mails enabled or users only get mail on mention and this is one ...
 		if !(user.EmailNotificationsPreference == user_model.EmailNotificationsEnabled ||
diff --git a/services/mailer/mail_repo.go b/services/mailer/mail_repo.go
index a5343f812..24e6d671f 100644
--- a/services/mailer/mail_repo.go
+++ b/services/mailer/mail_repo.go
@@ -31,6 +31,10 @@ func SendRepoTransferNotifyMail(doer, newOwner *user_model.User, repo *repo_mode
 
 		langMap := make(map[string][]string)
 		for _, user := range users {
+			if !user.IsActive {
+				// don't send emails to inactive users
+				continue
+			}
 			langMap[user.Language] = append(langMap[user.Language], user.Email)
 		}