I've seen several threads where someone tells about using cyrus imap... but everything I found wasn't very detailed, and I'm not sure if anybody really got ISPConfig running with cyrus imap.
First question: Anyone out here who did?
As far I could examine cyrus imap is much more scalable than courier is, because cyrus doesn't use standard Maildir, but some own, indexed format (although it seems to be quite similar)
But because of this indexing, you have to use either lmtp or cyrus' own deliver program to dispatch mails to the mailboxes, and as procmail is needed for antivirus, antispam, autoresponder, over quota messeges etc. I'm wondering if it might be possible to user cyrus anyway, e.g. by combining procmail and cyrus deliver oder using cyrus deliver filter methods for antivirus & co. I'm quite sure the latter would be possible by using sieve - but I guess it would be a real challenge to adapt the code...
So, next question: Anyone here who tried sth. of that? Regardless if sussessful or not?
Supposed anyone tried that and indeed got cyrus working - how is it possible to get quota working? Cyrus imap has its own quota management, updated with its own config program (or with a command of its program interface). I'm not sure if it's possible to enable quotas on user/group filesystem level as it's done with Maildir, because I believe that all mailbox files have the same system user - but that's sth. I'm not sure about that, but I'm currently just too lazy to check that right now.