dovecot - Dec 2013 - Use Replication plugin to do a backup (one-direction sync)

Hello, 

I have a setup where I need to have Server A (dovecot 2.1.7) replicated
on a Server B (dovecot 2.1.7). I know that I can do a per user backup
with: 

doveadm -D backup -u %u remote:mailmirror at serverB 

I would like to use Notify/Replication to backup only when there's
something new. I don't understad if the Replication plugin can be used
to do a backup server, or it's only of for two-way sync? 

My question is: It's possible to use Replication to do a backup
(one-direction sync)? 

Thanks 

Francesco