Author: W B Hacker Date: To: exim-users Subject: Re: [exim] combining multiple incoming messages to same local domain
Phil Pennock wrote: > On 2012-05-30 at 13:42 -0500, Don Walker wrote:
> [ same mail, multiple deliveries ]
>> Does anyone know a way for exim to combine such messages and process
>> them as a single arriving message addressed to multiple groups? Factors
>> for combining would include a short time window (ie, the split messages
>> arrive within seconds of each other), the same sender, and the same subject.
>
> No, not as Exim stands. Normally this sort of duplicate suppression is
> done in the storage system, rather than holding mail in the spool for
> longer.
>
> This is known as "single instance store", at the message-level rather
> than the attachment level. It will work unless the mail service
> provider is also rewriting Subject: headers for each variant mail.
>
> Cyrus IMAP will do this by default; it looks as though Dovecot might
> only do this for attachments, as an extension, but I don't really know
> Dovecot and could be wrong.
>
> -Phil
>
Of two SQL-driven MTA that (did) vie for a place at the table, one did
that, the other did not, and a dozen years on, I do not recall which.
The MUA built into 'Opera' did so (at one time), plus at least one
for-fee MUA. Swiss, and for Mac IIRC. 'Powermail' if memory serves.
Downside to single-store is that as that just as with certain types of
fs links, unintended losses can occur if/as/when the mechanism that
preserves that sole 'real' instance until the LAST deletion is executed
get munged - wiping out even what one THOUGHT was a safe and independent
copy in another folder.
As happens.
Server-side, Dovecot is safer than most on such issues, as it EXPECTS
its indices to become plucked now and then, so is in the habit of
rebuilding them from scan of wot it actually finds in storage rather
than a stale opinion as to what might have been believed before the
latest stumble.
