email registration updated

frontend/pweb/lib/pages/signup/form/email.dart

@@ -1,16 +1,16 @@
 
 import 'package:flutter/material.dart';
 
+import 'package:email_validator/email_validator.dart';
+
 import 'package:pweb/generated/i18n/app_localizations.dart';
 
-//TODO check with /widgets/username.dart
-
+//TODO: check with /widgets/username.dart
 class EmailField extends StatelessWidget {
   final TextEditingController controller;
 
   const EmailField({super.key, required this.controller});
 
-  static final _emailRegex = RegExp(r'^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$');
 
   @override
   Widget build(BuildContext context) {
@@ -22,7 +22,7 @@ class EmailField extends StatelessWidget {
         hintText: AppLocalizations.of(context)!.usernameHint,
       ),
       validator: (value) {
-        if (value == null || !_emailRegex.hasMatch(value)) {
+        if (value == null || !EmailValidator.validate(value)) {
           return AppLocalizations.of(context)!.usernameErrorInvalid;
         }
         return null;