diff --git a/controllers/addOfficeHourHandler.go b/controllers/addOfficeHourHandler.go
index 0025ac2..0707abe 100644
--- a/controllers/addOfficeHourHandler.go
+++ b/controllers/addOfficeHourHandler.go
@@ -124,7 +124,7 @@ func (b *BaseHandler) AddOfficeHourHandler(w http.ResponseWriter, req *http.Requ
 	if err != nil {
 		email = &mail.Address{Name: "", Address: req.FormValue("email")}
 		errors = append(errors, "Mailaddresse konnte nicht geparst werden.")
-	} else if !(strings.HasSuffix(email.Address, "@"+b.config.Tutor.MailSuffix) || strings.HasSuffix(email.Address, "."+b.config.Tutor.MailSuffix)) {
+	} else if !(b.config.Tutor.MailSuffix == "" || strings.HasSuffix(email.Address, "@"+b.config.Tutor.MailSuffix) || strings.HasSuffix(email.Address, "."+b.config.Tutor.MailSuffix)) {
 		errors = append(errors, fmt.Sprintf("Mailaddresse muss auf „%s“ enden.", b.config.Tutor.MailSuffix))
 	}
 	info := req.FormValue("info")