I asked Open-Xchange about the supposed removal of the replication function in dovecot and they responded like this: "I think there was a misunderstanding. Sync will only be removed in the Pro version starting from version 3.0 and replaced by the mandatory use of object storage (S3, Scality, etc.). The new Dovecot Pro version, although announced by March 2023 , has not yet been released and we have not been given a firm release date. As far as I know, nothing changes in the Dovecot Community Edition. Then you should be able to continue working with the current Dovecot version as usual." So fortunately there should be no problems in the future.
Sync != replicatior Their Wiki states the opposite of what Open-Xchange responded to you. But let's see what in the end will really happen...
Thanks. I can confirm enabling testing repo for deb12, running apt-update, updating only dovecot package to test version did work. Previously I had the same problem as you. what I did: nano /etc/apt/sources.list replace bookworm with testing to enable test repo apt update apt install -t testing install dovecot-imapd dovecot-pop3d nano /etc/apt/sources.list replace testing back to bookworm to disable test repo Additionally i reconfigured services with: ispconfig_update.sh --force that's it, now it works.
I received a very clear response from OX (Open-Xchange) and I believe that the misunderstanding can be considered closed. My interlocutor, an OX reseller, sent me the exchange he had directly with OX, asking me to summarize without directly posting what I received because it was an internal exchange. The first answer, already very clear, I followed up with a second request for further information to which I attached our dovecot.conf configuration file and this how-to https://www.howtoforge.com/tutorial/ispconfig-multiserver-setup-debian-ubuntu/3/ to be absolutely sure that our configurations exclusively use doveadm-sync technology i.e. dsync because the whole issue revolves around this. The good news is that certainly nothing has changed for dsync and nothing will change in the future, this was reiterated to me unequivocally. The misunderstanding arises from the fact that OX does not consider dsync a real replication functionality but simply a way of copying email messages between two servers which, when used bidirectionally (server 1 copies to server 2 and server 2 copies to the server 1) emulates a replication functionality. The real replication technologies according to them are Dovecot Director (which will be discontinued in CE and replaced in PRO by the Palomar architecture) and Replication or Replicator (which is discontinued in CE and has never been supported in PRO): both have nothing to what to do with dsync, and are the subject of the discontinuation communication from the CE version that generated the misunderstanding. So dsync will be supported in the future by the CE version exactly as it has been until now. Without prejudice to all this, I make a personal observation that is inspired by what happened in Debian 12 with the dovecot 2.3.19.1 version (synchronization problems with the opening of new mailboxes) and by the insistence with which OX, in all the replies received by me, limits dsync to the simple mail migration functionality as if the bidirectional copy were almost a stretch (which is instead fully foreseen on this official page https://doc.dovecot.org/3.0/man/doveadm-sync.1/). There could be a conflict of interest between the bidirectional copy functionality offered by the CE with dsync (which as we know emulates replication perfectly) and the commercial PRO version which contains the actual replication technology and this conflict of interest could be the basis of the unclear communication that generated the misunderstanding. So we can safely continue to use dsync, but let's keep our eyes open to understand whether it was exclusively a simple problem in communication or whether it is a sign of possible future changes (which today, however, as far as dsync is concerned, are absolutely excluded by OX) . I hope I have been useful.
Thank you very much for this detailed report. I want to add, that you can find a working dovecot also in "bookworm-backports", which can be added permantly ;-)
