Dear Till, we have an debian ispconfig single server setup (one mail server). We want to setup another mailserver acting as an archive server, with the same email accounts (mailboxes) and the same email domains on the same internal lan subnet, different server ip and server hostname. We are planning to use imapsync to transfer emails which are "expired" (i.e. after 6 months or so) from the first mail server to this archive mail server. Would you recommend to use a master-slave replication or a setup like the master-master scenario omiting the dsync and unison part? https://www.howtoforge.com/tutorial...abase-cluster-on-debian-8.4-with-ispconfig-3/ In case we had a master-slave scenario how could we force the second server to be a replica of the master-mail server for mailboxes, aliases, passwords, email domains, etc? If we cannot have a replica of the first server then, we are planning to use another mail domain for the archive server i.e. the master domain is example.com and the archive domain is archive.example.com. This means we have to recreate all mailboxes from the master server to the archive server and moreover we need to keep the passwords in sync, which is not very convenient. Would you think of another solution according to your experience? Thank you in advance for your support, Panos.