maildomain-permissions acting strangely & user_insert returns wrong maildirowner

[till]

I guess that the maildir with wrong permissions gets created by the lda (deliver if you use dovecot) while the correct one gets created by ispconfig. As ispconfig does not change the directory or permissions when the maildir already exists, then the wrong permissions are kept. what you can try is to add a forced permission update in ispconfig on the maildir path in the insert function of the mail plugin.