sync_log_chain - is it always needed?

[Olaf Frączyk]

Hello,

I was wondering why do we need to use this option on middle servers in 
replication chain?

I don't use sync_server. The replication is done using IMAP protocol. Is 
in this case this setting also necessary?

Shouldn't the middle server catch all changes that are done via IMAP 
protocol and forward them to the next server in the replication chain?

BTW. Does anyone has some description how sieve scripts replication is 
done via IMAP protocol?

Best regards,

OIaf