Is there a way in ispconfig to define and use an alias name rather than the mailaddress to login to the mailaccount. Would be perfect if I can define alias or mailaddress to login for each account.
yes I read that, but does your answer mean that there is no way to do that? If that feature isn't implemented yet, is it possible to add?
Make a feature request in the developer bug database. Try to find reasons why that feature would be useful.
realized that when using custom login name diffrend for mailaddress both can be used for login. Is it posslibe to avoid login with mailaddress if custom login is set?
I don't think this is possible without modifying the code. Why is it a problem if the user has 2 logins?
For old style security reasons, so attackers need password AND matching login name - old/simple "two factor" authentication.
...because some people only accept mailaddress as username, others want the alias for better security..
The alternative username feature has been implemented to allow the import from account data from other control panels into ISPConfig that do not support the email address as a username so that it can be avoided at import time that all users have to change the username in the mail client. Feel free to make a feature request in our git system at git.ispconfig.org in case such a feature request does not exist already.