Duplicate mails

Dannik

Verified User
Joined
Jan 7, 2009
Messages
77
Location
Netherlands
Hi,

Every now and then (this differs per day), I recieve duplicate mails. First I thought something could have gone wrong using forwarders, but I noticed that it also appears when mails were send directly to the apropriate mailbox. This also happens when I send the mails to myself (from another account/server).
The duplicate message is exactly the same, however the receiving id and the delivery date are different. Most times there seems to be a delay for approx. 8-10 minutes.
Is anyone familiair with this kind of behaviour?

The code from both mails are as following:
Return-Path: <[email protected]>
Delivered-To: [email protected]
Received: from server03.againotherdomain.tld
by server03.againotherdomain.tld with LMTP
id 1KsvH5HMO1suDQAAkS2Xqg
(envelope-from <[email protected]>)
for <[email protected]>; Tue, 03 Jul 2018 21:20:49 +0200
Return-path: <[email protected]>
Envelope-to: [email protected]
Delivery-date: Tue, 03 Jul 2018 21:20:49 +0200
Received: from server01.againotherdomain.tld ([my-server-ip])
by server03.againotherdomain.tld with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256)
(Exim 4.91)
(envelope-from <[email protected]>)
id 1faQqy-0003Oi-SK
for [email protected]; Tue, 03 Jul 2018 21:20:49 +0200
DKIM-Signature: <snipped>
Received: from *my address at home* helo=[192.168.25.5])
by server01.againotherdomain.tld with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128)
(Exim 4.91)
(envelope-from <[email protected]>)
id 1faQqy-0004C6-Ac
for [email protected]; Tue, 03 Jul 2018 21:20:44 +0200
Message-ID: <[email protected]>
Date: Tue, 03 Jul 2018 21:20:46 +0200
From: Danny Simons <[email protected]>
MIME-Version: 1.0
To: [email protected]
Subject: test2
Return-Path: <[email protected]>
Delivered-To: [email protected]
Received: from server03.againotherdomain.tld
by server03.againotherdomain.tld with LMTP
id wiNJGGLOO1s1MwAAkS2Xqg
(envelope-from <[email protected]>)
for <[email protected]>; Tue, 03 Jul 2018 21:28:34 +0200
Return-path: <[email protected]>
Envelope-to: [email protected]
Delivery-date: Tue, 03 Jul 2018 21:28:34 +0200
Received: from server01.againotherdomain.tld ([my-server-ip])
by server03.againotherdomain.tld with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256)
(Exim 4.91)
(envelope-from <[email protected]>)
id 1faQqy-0003Oi-SK
for [email protected]; Tue, 03 Jul 2018 21:20:49 +0200
DKIM-Signature: <snipped>
Received: from *my address at home* helo=[192.168.25.5])
by server01.againotherdomain.tld with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128)
(Exim 4.91)
(envelope-from <[email protected]>)
id 1faQqy-0004C6-Ac
for [email protected]; Tue, 03 Jul 2018 21:20:44 +0200
Message-ID: <[email protected]>
Date: Tue, 03 Jul 2018 21:20:46 +0200
From: Danny Simons <[email protected]>
MIME-Version: 1.0
To: [email protected]
Subject: test2
Regards,
Danny
 
Hi Martynas,
The problem has been there for a while. After the latest updates (using CB) a few weeks ago I thought the problem got less, but at the beginning of this week, when 2.3.2. came out I updated it directly (again using CB). Since then the problem seems to be back. It's not every mail that comes in duplicate, but I think about 5% (wild guess!)...

edit:
I looked into the Exim logs and for a certain message I received today twice and I found this:
2018-07-05 11:28:34 cwd=/var/spool/exim 2 args: /usr/sbin/exim -qG
2018-07-05 11:28:43 1fb0Z1-0007LH-15 <= 0100016469c590fd-13be9f15-07a6-476f-81d4-87ded32cd20e-000000@mailer.netflix.com H=a14-232.smtp-out.amazonses.com [54.240.14.232] P=esmtps X=TLSv1.2:AES128-SHA:128 CV=no S=81089 DKIM=amazonses.com id=0100016469c590fd-13be9f15-07a6-476f-81d4-87ded32cd20e-000000@email.amazonses.com T="Netflix vanavond?" from <0100016469c590fd-13be9f15-07a6-476f-81d4-87ded32cd20e-000000@mailer.netflix.com> for [email protected]
2018-07-05 11:28:43 cwd=/var/spool/exim 3 args: /usr/sbin/exim -Mc 1fb0Z1-0007LH-15
2018-07-05 11:28:43 1fb0Z1-0007LH-15 == [email protected] R=virtual_user T=dovecot_lmtp_udp defer (-1): LMTP connection closed after end of data
2018-07-05 11:43:34 cwd=/var/spool/exim 2 args: /usr/sbin/exim -qG
2018-07-05 11:58:34 cwd=/var/spool/exim 2 args: /usr/sbin/exim -qG
2018-07-05 11:58:34 1fb0Z1-0007LH-15 => dannys <[email protected]> F=<0100016469c590fd-13be9f15-07a6-476f-81d4-87ded32cd20e-000000@mailer.netflix.com> R=virtual_user T=dovecot_lmtp_udp S=82907 C="250 2.0.0 <[email protected]> +HDYGsrrPVtLbgAAkS2Xqg Saved"
2018-07-05 11:58:34 1fb0Z1-0007LH-15 Completed

Like Dovecot, everything is up to date on this server :)
 
Last edited:
The Dovecot 2.3.2. does not fix the issue, incoming emails still got duplicates unfortunately.
 
Maybe it's relevant: I'm running Exim 4.91 with latest rewrite of Exim.conf regarding Spamblocker, without modifcations.
Code:
# SpamBlockerTechnology* powered exim.conf, Version 4.5.9
# April 13, 2018

Danny
 
The bug introduced in Dovecot 2.3.x, the only solution available for us is to downgrade to 2.2.x. If you have another solution please share it.
 
Yes, that is the most confusing. I don't see the issue on all the servers with Dovecot 2.3.x, some servers are affected, others are not. Probably there is something else beside our scope yet.

Never succeeded to manually replicate the issue. Not all the emails are duplicated, only random duplicates had we.
 
Yes, that is the most confusing. I don't see the issue on all the servers with Dovecot 2.3.x, some servers are affected, others are not. Probably there is something else beside our scope yet.

Never succeeded to manually replicate the issue. Not all the emails are duplicated, only random duplicates had we.

I agree with that. I have 2 servers running the same configuration, but the problem persists on just one of them.


Thanx! Installing the update at this very moment. I will report within a few days if there's any progress :)
 
I agree with that. I have 2 servers running the same configuration, but the problem persists on just one of them.
Having said that, on the second server the issue also appeared in the mean time.

However, I installed the latest version of Dovecot on both servers and as far as I can see the problem seems to be gone now :)
Danny
 
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