Is it OK for users to use either of a pair of replicated servers ?

[John]

Hello, I have just set up a second server for a small email group and I 
now have replication working between them. I was very happy to note that 
it replicates both ways.

My use-case is basically this: to have two servers, one acting as a 
primary and another as a backup. The primary will be the one that goes 
out to the internet to grab emails for users. Apart from that difference 
the two servers are identical. Either can take on the primary role. 
Users can connect their IMAP email clients to either server. One of the 
pair runs sync_server and the other regularly connects to it to keep the 
two servers in sync. It's a basic configuration intended for use by a 
small number of people.

I'd like to confirm that the replication mechanism implemented with 
sync_server and sync_client is ok for this kind of set-up. It certainly 
appears to work just fine like this but I haven't found anything in the 
documentation saying that two-way replication like this is ok (i.e. 
where users can log in to either server).

Many thanks.