Issue Group mail problem

[xemorytr]

Server operating system version

Ubuntu 22.04.2 LTS

Plesk version and microupdate number

Version 18.0.54 Update #2

Hello ,

We use an e-mail address as a group mail. The subject of the incoming mail and the content of the incoming mail are normal.
We forward the group mail to an additional person. In the e-mail he received, the subject title is correct, but the incoming e-mail address is =?utf-8?b?IlRpY2FyZXQgQmFrYW5sxLHEn8SxIELEsExHRSBTaXN0ZW1pIiA8YmlsZ2VA?=@server.com, =?utf-8?b?[email protected] This changes as a different character in each mail.
It only does this in an email from a company.
This is the case when the mail / plesk domain group mail from [email protected] forwards [email protected] to the same domain mail within itself, [email protected].

Do you have a suggestion for a solution? Thanks in advance.

 

[xemorytr]

annotation information:
MIME-Version: 1.0
From: =?utf-8?b?IlRpY2FyZXQgQmFrYW5sxLHEn8SxIELEsExHRSBTaXN0ZW1pIiA8YmlsZ2VA?=@server.com,
[email protected]

 

[Peter Debik]

Am I right that this does not apply to all mails that you receive but only to some from the same sender? Could it be possible that the header of the incoming mail was not properly encoded?

Have there every been any custom modifications to your /etc/postfix/main.cf file? Some users tweak it to accomodate certain character encodings.

 

[xemorytr]

Hello @Peter Debik

The mail to the group mail is fine, but that mail is forwarded to a few people.
but only that e-mail title and address look like this.
main.cf there was no change.
This is how the system automatically forwards the mail.
this only applies to a forwarded e-mail address and header.

 

[Peter Debik]

I don't know what you mean with "only that e-mail title and address". Are all emails affected or are only some emails affected, e.g. only emails that are sent from a certain domain or account?

I cannot find any standard solution in our documents here on this. Maybe it is best if you open a support ticket or wait if someone else on the forum has a solution.

 

[xemorytr]

@Peter Debik

There is no problem with the e-mail sent to the e-mail address.
Everything is normal.
When this mail is also forwarded by the system, it changes the system in this way and falls into the inbox.
No problem when another e-mail arrives.
It just does it specific to an email address.

 

[Peter Debik]

I understand that the issue only occurs when emails arrive from one specific sender, but not from other senders. And only if these emails from that one sender are forwarded, the header character encoding is changed.

In that case the issue is a wrong header encoding by the sender.

 

[xemorytr]

@Peter Debik I understand that the issue only occurs when emails arrive from one specific sender, but not from other senders. And only if these emails from that one sender are forwarded, the header character encoding is changed. // yes

The problem starts when the content of the mail sent to this main mail / this is forwarded.

Return-Path: <incoming e-mail address>
X-Original-To: group email address
Delivered-To: group email address
Received: from hostname (localhost [127.0.0.1])
by hostname (Postfix) with ESMTP id D1EAF203818
for <group email address>; Wed, 2 Aug 2023 10:52:21 +0300 (+03)
Authentication-Results: hostname;
spf=pass (sender IP is 127.0.0.1) smtp.mailfrom=prvs=95787fb5b2=b@tr smtp.helo=hostname
Received-SPF: pass (hostname: localhost is always allowed.) client-ip=127.0.0.1; envelope-from=prvs=95787fb5b2=be@t; helo=hostname;
X-Spam-Flag: NO
X-Spam-Score: 0
X-Spam-Level:
X-Spam-Status: No, score=x tagged_above=-9999 required=5 WHITELISTED tests=[]
autolearn=unavailable
Received: from hostname ([127.0.0.1])
by hostname (hostname [127.0.0.1]) (amavisd-new, port 10024)
with ESMTP id lLEiv4_xKUgb for <group email address>;
Wed, 2 Aug 2023 10:52:21 +0300 (+03)
Received: from incoming e-mail address (incoming e-mail address [ip])
by hostname (Postfix) with ESMTPS id 6D4FD20381D
for <group email address>; Wed, 2 Aug 2023 10:52:21 +0300 (+03)
Received-SPF: pass (hostname: domain of domain designates ip as permitted sender) client-ip=ip; envelope-from=prvs=95787fb5b2=be@tr; helo=mail2.tr;
X-AuditID: ac1e0122-259ff70000002f48-c4-64ca0b32ce61
Received: from S00EXCH05.xxx.local (S00EXCH05.xxx.local [ip])
(using TLS with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
(Client did not present a certificate)
by domain (domain) with SMTP id D2.E8.12104.23B0AC46; Wed, 2 Aug 2023 10:52:21 +0300 (+03)
Received: from S00EXCHECP.xxx.local (ip) by
S00EXCH05.xxx.local (10.224.89.25) with Microsoft SMTP Server
(version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id
ip; Wed, 2 Aug 2023 10:52:15 +0300
Received: from S00EXCH09.xxx.local (ip) by
S00EXCHECP.xxx.local (ip) with Microsoft SMTP Server
(version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id
ip; Wed, 2 Aug 2023 10:52:15 +0300
Received: from S99WEBSRV01 (ip) by S00EXCH09.xx.local
(ip) with Microsoft SMTP Server id 15.2.1258.16 via Frontend
Transport; Wed, 2 Aug 2023 10:52:15 +0300
MIME-Version: 1.0
From: "Ti" <mail adress >
To: <group mail adress>, <group email address>
Date: Wed, 2 Aug 2023 10:52:15 +0300
Subject: Be
Content-Type: text/html; charset="utf-8"
Content-Transfer-Encoding: base64
Message-ID: <[email protected]>
X-CFilter-Loop: Reflected

 

[Peter Debik]

Thank you for providing more information. In this case however, probably this header segment does not help to find the root cause. You'll probably need to find out more about the sender's configuration and the header that the sender is sending in his mail and then examine why this cannot be decoded properly. I am not sure if it is worth your time, because chances are that it is not your server that has an issue, but the sender's outgoing mail configuration.

 

[Kaspar]

@xemorytr can you give more details on your setup? How did you create and use the 'group email address'? And how are you forwarding mails to the 'additional person'? Can you give a step by step overview of how emails are send in this setup?

 

[xemorytr]

@xemorytr can you give more details on your setup? How did you create and use the 'group email address'? And how are you forwarding mails to the 'additional person'? Can you give a step by step overview of how emails are send in this setup?

There really isn't much detail.
Everything is on plesk.
a domain name, the e-mail address of that domain, its group mail and forwarding to 2 people.
all of these jobs are configured through plesk.
As I said, there is only one mail problem.
You do not have this problem with the e-mails you receive from other companies.
This is what happens when the incoming mail is forwarded to that person by plesk.
there was no problem before.
no updates were made. (only plesk updates done)

 

[xemorytr]

@Kaspar Group mail everything is fine.

but when the same mail goes to another recipient in the same domain, different names and recipients

 

[Peter Debik]

Thank you for the screenshots. The screenshots reveal that actually the recipient names are not "normal" as said in the first post, but they contain different UTF-8 characters beyond the ASCII or Western European charset. This can create a lot of problems with charset interpretation when such emails are processed further.