One way dsync replication with dsync -R

[Wolfgang Hennerbichler]

Hi dovecot users, 

I’ve found the -R parameter for dsync. Does this enable one-way syncing if enabled on the slave in replication_dsync_parameters? The documentation doesn’t mention much what happens if I enable this on the “replciation slave”. 

Before you ask: Two way synchronisation causes issues in my installation (see the unanswered thread here: http://www.dovecot.org/list/dovecot/2017-March/107431.html), it causes unread, deleted messages to re-appear. I would hope that one-way synchronisation would avoid this, but I’d also like to know if the -R parameter is safe to use. 
I am also still wondering if anybody has a perfectly working 2-way-synchronised dovecot installation (and I’m interested in your dovecot -n). 

wogri