Issue Messages with Unicode unable to pick up via IMAP after upgrade

[SacAutos]

I updated one of my CentOS 6 servers recently to Plesk Obsidian. One of my customers has reported that since then, he's getting some messages with this notice embedded with it instead of his email:

From: Mail Delivery Subsystem <postmaster>
Subject: Cannot display Unicode content

This E-mail message was determined to be Unicode-formatted
but your E-mail reader does not support Unicode E-mail.

Please use an E-mail reader that supports POP3 with UTF-8
(see RFC 6856 - Post Office Protocol Version 3 (POP3) Support for UTF-8).

This can also happen when the sender's E-mail program does not
correctly format the sent message.

The original message is included as a separate attachment
so that it can be downloaded manually.


Followed by a Mail Attachment which is the body of his message. What's the fix for this one?

 

[Ales]

Which e-mail client does your customer use? Is this occurring with more than one sender?

Is the message normally visible when using webmail to read it?

Anyway, I suspect this is not a server issue...

 

[SacAutos]

He's an Apple user. He's reporting this on his desktop, laptop and mobile devices.

 

[SacAutos]

I talked with my customer again this morning. The issue is also happening with other users who have Android devices as well. Feels like a server issue to me. Yesterday I found this which generates the exact message my customer has been receiving: Courier IMAP server: libs/imap/pop3dserver.c | Fossies

 

[SacAutos]

What's super frustrating about this problem is that I created another mailbox on his domain for my testing. Then I copied a bunch of email messages that we know generate the Unicode error message to that box. Then I picked them up using my (Apple) desktop. They all came through fine. Not what I was expecting.

Just for reference, I'm attaching a screenshot from his iPad's mail app that shows all the message titles.

 

[Stefan Müller]

Hey there,

got some customers who experience a similar issue.

They are reporting that since the update to obsidian they're receiving the following message:

Your IMAP client does not appear to correctly implement Unicode messages, see RFC 6855 - IMAP Support for UTF-8

They are using Outlook 2010, 2013 & Office365.

In Addition the the "Umlaute (Ä, Ö, Ü) are displayed as hieroglyphics.

Are there any issues or workarounds for that thingy?

Thanks in advance,

Stefan

 

[moswak]

we have also customers reporting that since the update to obsidian they're receiving the following message:

This E-mail message was determined to be Unicode-formatted but your E-mail
reader does not support Unicode E-mail.

Please use an E-mail reader that supports POP3 with UTF-8 (see
RFC 6856 - Post Office Protocol Version 3 (POP3) Support for UTF-8).

we use:

CentOS Linux 7.7.1908
Plesk Obsidian Version 18.0.20
courier-imap 5.0.8-2.centos.7+p18.0.20.0+t191018.1712
postfix 3.4.5-2.centos.7+p18.0.19.0+t190904.1310

 

[Ales]

Was anyone able to recreate this issue - so that we could test more easily, without involving the actual customers?

Perhaps it would help if we could determine if there is a common setting or a piece of software involved.

Could you all please post as much as you can about the system(s) involved?

So, OS and OS version, Plesk version, IMAP server and version, e-mail client version... Also any relevant settings that you can think of, e.g. is SNI used, etc.

 

[sebgonzes]

Was anyone able to recreate this issue - so that we could test more easily, without involving the actual customers?

Perhaps it would help if we could determine if there is a common setting or a piece of software involved.

Could you all please post as much as you can about the system(s) involved?

So, OS and OS version, Plesk version, IMAP server and version, e-mail client version... Also any relevant settings that you can think of, e.g. is SNI used, etc.

The problem is with courier and seem, microsoft outlook : Issue - Your IMAP client does not appear to correctly implement Unicode messages, see https://tools.ietf.org

 

[SacAutos]

My server is CentOS 6, all current patches applied. Current Plesk Obsidian. MTA is Postfix. Client mail apps are Apple Mail (on MacOS Mojave) and Mail on iPad IOS 13.

 

[sebgonzes]

My server is CentOS 6, all current patches applied. Current Plesk Obsidian. MTA is Postfix. Client mail apps are Apple Mail (on MacOS Mojave) and Mail on iPad IOS 13.

Postfix is for smtp.... you had to review your imap server (dovecot o courier, I suppose that is courier with this problem)

 

[Phantasia]

I received the same system notification in Outlook 360. I've updated Plesk to Obsidian a couple of days ago. I use courier-imap (5.0.8-v.ubuntu.18.04+p18.0.20.0+t191018.1712). Also, Horde (5.2.17) webmail gives an error message in red: "IMAP error reported by the server. "
For the latter I've just found this article: Horde Inbox does not display any email: IMAP error reported by server

 

[SacAutos]

I see that there was an update installed overnight that specifically addresses this problem. Can anyone confirm that this issue was fixed on their servers?

 

[Jose Isla]

I installed a few minutes ago that update and until tomorrow with the client I can not confirm if it solves the problem, but I think it only resolves the names of the folders in Horde with courier-imap ....

 

[SacAutos]

I checked with my customers. The issue that is the subject of this thread is still broken. An earlier issue that I also reported relating to Horde has been fixed. Still waiting...

 

[Jose Isla]

I have consulted with my clients and the alert message continues to appear ... the problem of folder names solved. We still waiting...

 

[SacAutos]

More customers are starting to complain. Here's an example of the message they receive. Any ETA on a patch?

 

[Jose Isla]

we still waiting, we have the same alert messages for two weeks ...

 

[Erwan]

Hi,
Same problem for us...

 

[Erwan]

Ales, Igor,
Do you have an ETA on patch?