On Wednesday 30 January 2008 18:14:19 you wrote:

On Wed, 30 Jan 2008, Anne Wilson wrote:

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On Tuesday 29 Jan 2008, you wrote:

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On Tue, 29 Jan 2008, Anne Wilson wrote:

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I have a problem and I don't know which part of the mail chain could be causing it, although dovecot does seem to be the most logical source.

I get multiple copies of messages to my Inbox. I have just deleted 24 copies of a newsletter from Computer Shopper. The worst example I have seen of this had more than 90 copies. This doesn't happen to any subfolder of Inbox, just Inbox itself.

The problem started about 10-14 days ago, on the old mail server (running Mandriva 2007.1). The new server runs CentOS and exhibits the same problem.

I'd be interested in any comments, as my efforts to track it down have got nowhere.

Are you using Dovecot's 'deliver' as your LDA (local delivery agent)? Otherwise I'd suspect the problem lies in whatever you're using for your local deliveries, creating some kind of mail loop. Check your .forward/.qmail/.procmail/whatever files. I haven't heard of/seen dovecot duplicating messages unless there are actually multiple copies in your mailbox.

Everything looks fine, and remember that this started on a server that had been running correctly for a long time.

Yes, but these aren't hard-coded things. It's usually a configuration change of some sort that results in inadvertent loops.

Fair comment. I did look when you suggested it, but I'll go through everything again in the morning.

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If your LDA isn't already doing so, add a 'Delivered-To' or 'X-Mail-Loop' header at each stage, so you can more easily tell if this is what's happening.

How/where do I do that?

With procmail, you could add something like:

fw means filter and wait

:0fw : | formail -fbA "Delivered-To: (information here)"

(e.g. in my case '(information here)' would be 'dovecot@benizi.com')

OK, thanks. I'll try that tomorrow, too.

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And then (I assume you've done this, but it should be said) look at the headers of the duplicated messages to see if they're 1) actually distinct messages [external problem] 2) being delivered multiple times

They appear to be single messages, delivered multiple times. See my reply to Asheesh Laroia.

Forthcoming? I don't see a reply on-list.

Apologies. It seems that I forgot to switch on list management in kmail.
I've re-sent the message, this time to the list. It should arrive along with this.

BTW, one of the pairs of messages I compared in that message now has 30 copies in my inbox - two this morning, when I wrote the message.

Anne