We like to set up our mail system in two datacenters but the wikihttps://wiki.dovecot.org/Replication says "Shared folder replication doesn't work correctly..."

I'm thinking about using an external loadbalancer to ensure that only one host will get connections.

Normal operations: client ==imap=> loadbalancer ==imap=> host1 ==replication=> host2

Host1 or Datacenter1 is down: client ==imap=> loadbalancer ==imap=> host2

I see possible problems if host1 comes back and clients connect to host1 before the replication has caught up. But in our case that will be acceptable.

Do you consider my idea as safe for production use? Has anybody real world experience with such a setup? Is there a better way to replicate shared folders?

Thank you in advance for spending your time on thinking about my problem.

Axel