Mail server migration and HOLDing mail at Mailscanner

[Peter Lemieux]

If the recipient server used SMTP, then Postfix would handle everything 
itself.  It would queue up the mail until the dbmail server came back online 
and deliver it soon thereafter.  All SMTP servers know how to handle outages 
on the receiving end and queue up mail for later delivery. Reading a bit of 
the wiki page for LMTP, it looks pretty similar to ESMTP.  I'd bet you'd be 
fine just bringing the dbmail server down gracefully, but maybe you should run 
a test.

How about bringing down the server late some night when it has low volumes 
then sending a test message to an account on it from outside?  The Postfix 
logs will tell you what it did with the message both when it arrives and later 
after the dbmail server is brought back up.

Good luck, Simon!

Peter


On 03/07/2016 08:41 PM, Simon Buchanan wrote:
> Hi There,
>
> We have Mailscanner/postfix setup on centos and working well. It delivers mail
> to two seperate mail servers (dovecot and dbmail) depending on the domain
> (most clients are on our new dovecot platform, a few are on our old dbmail
> platform).
>
> dovecot is delivered via smtp:xxx.xxx.xxx.xxx
> dbmail is delivered via a dbmail-lmtp service: dbmail-lmtp:xxx.xxx.xxx.xxx:24
>
> We are about to perform a lengthy migration of the dbmail server, and need to
> simply stop Mailscanner processing mail for dbmail  until we are back up and
> running again. Is there anyway todo this, or is this a postfix question?
>
> Thanks!
>
> Simon