Trying to track down source of duplicate messages

[Timo Sirainen]

On 1 Apr 2019, at 19.40, Alex via dovecot <dovecot at dovecot.org> wrote:
> 
> Hi,
> 
> I haven't received any responses to my duplicate messages problem. It
> occurred to me that I posted my full dovecot config instead of just
> the changes we've made locally. I thought it might help to follow up
> with just the specific config to make it easier to identify a
> potential problem.

How are you delivering the mails? With dovecot-lda or something else? Do you see any errors/warnings in your MTA log? Similar problems at least can happen if the delivery takes a very long time and MTA times out and retries the delivery later on, but the original delivery actually succeeded eventually. You might see these differences in Received headers.