thx 4 your reply; if I try to logon by "firstname.lastname@example.org" the result is exactly the same. Squirrel checks that there's a "dom.tld" extension and does nothing in this case obviously.
But it seems to me, for authentication I need the exact "web1_test" string as user value, since ISPconfig does not support usernames as email addresses? How come these together?
bye & greetings