Allow unicode email addresses

app/src/main/java/eu/faircode/email/FragmentIdentity.java

@@ -70,7 +70,6 @@ import java.security.cert.X509Certificate;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
-import java.util.regex.Pattern;
 
 import javax.mail.internet.AddressException;
 import javax.mail.internet.InternetAddress;
@@ -758,11 +757,8 @@ public class FragmentIdentity extends FragmentBase {
                 //    throw new IllegalArgumentException(context.getString(R.string.title_no_name));
                 if (TextUtils.isEmpty(email) && !should)
                     throw new IllegalArgumentException(context.getString(R.string.title_no_email));
-
-                Pattern pattern = (unicode ? Helper.EMAIL_ADDRESS_UNICODE : Helper.EMAIL_ADDRESS);
-                if (!pattern.matcher(email).matches() && !should)
+                if (!Helper.EMAIL_ADDRESS.matcher(email).matches() && !should)
                     throw new IllegalArgumentException(context.getString(R.string.title_email_invalid, email));
-
                 if (TextUtils.isEmpty(host) && !should)
                     throw new IllegalArgumentException(context.getString(R.string.title_no_host));
                 if (TextUtils.isEmpty(port))

app/src/main/java/eu/faircode/email/Helper.java

@@ -195,21 +195,13 @@ public class Helper {
     static final Pattern EMAIL_ADDRESS = Pattern.compile(
             "[\\S]{1,256}" +
                     "\\@" +
-                    "[a-zA-Z0-9][a-zA-Z0-9\\-]{0,64}" +
+                    "[\\p{L}][\\p{L}0-9\\-\\_]{0,64}" +
                     "(" +
                     "\\." +
-                    "[a-zA-Z0-9][a-zA-Z0-9\\-]{0,25}" +
+                    "[\\p{L}0-9][\\p{L}0-9\\-\\_]{0,25}" +
                     ")+"
     );
 
-    static final Pattern EMAIL_ADDRESS_UNICODE = Pattern.compile(
-            "([\\p{L}\\_\\.\\-\\d]+)" +
-                    "@" +
-                    "([\\p{L}\\-\\.\\d]+)" +
-                    "((\\.(\\p{L}){2,63})+)"
-            // ^([\p{L}\_\.\-\d]+)@([\p{L}\-\.\d]+)((\.(\p{L}){2,63})+)$
-    );
-
     private static final ExecutorService executor = getBackgroundExecutor(1, "helper");
 
     static ExecutorService getBackgroundExecutor(int threads, final String name) {