Sorry for CC'ing those who replied on this thread, but I just wanted to note
something important, for all who replied on that thread. And since it's been
three days since the original post, I wanted to make sure everyone get this.
So regarding the sync of control files in a cluster environment, some said
they use nfs to share those directories, other recommended using rsync etc.
All this is fine except for one thing. qmail-send needs to be restarted (on
every server in the cluster running qmail/vpop) to start accepting mail for
the newly added domain (to reread control/rcpthosts at least).
So I think you cannot just sync those files and expect everything to work as
I recall a old problem from the days of vpopmail 4.9.x which was a bug in
vadddomain not sending a HUP signal to qmail-send to tell it to reread
The problem manifested itself when a new domain is added, then you try to send
a message to a mailbox at that domain, qmail typically refused the delivery
saying something like:
"Although I am listed as best preference MX for this domain, it's not listed
in my rcpthosts", or similar.
Suppose you did ./vadddomain on one of the cluster servers running qmail/vpop.
Sure if you use NFS, the changes will show from any of the servers running the
NFS client. However, only the server which you ran vadddomain on will have
it's qmail-send restarted and it will be the only one that will receive mail
for that domain. The others will not untill qmail-send is restarted, or the
server is rebooted.