eventually fix the mailman bug which is there since plesk 8
After every update to plesk I have to manually fix the mailman entry in /etc/postfix/master.cf
It should read: mailman unix - n n - - pipe flags=Ru
plesk updates change the flags=R which means that mailing lists are broken if they contain upper case characters.
As far as I know problems in mixed cases in Plesk mail services have been fixed. Have you checked this issue in Plesk 12.5 Preview (http://download1.parallels.com/Plesk/PP12/parallels-plesk-12.1-for-linux-change-log.html) ? If it is reproduced – please write step-by-step instruction how we can check it. Thanks.
UPD: We are closing the request as completed, since no information to the contrary were provided for over a month.