Chaning from ldap pam to pam authentication

Hello,

so far I used pam_ldap.so for authentication. nsss then imports all ldap users.

My Ldap Server went down today, so I want to migrate to a system that
uses users in /etc/passwd. I created a user something.something and I can log in with pam.

But when I try to login via dovecot I get the error message: pam:
unknown user. I think its probably because its trying to authenticate
something@something@example.com which does not exist.

How do i fix that?

Thank you. Best, Lucienne