[bug]: Cyrillic encoding is broken

[flover97]

What happened?

The encoding breaks on the subject, body of the letter and attachments. In the UTF-8 encoding, everything works normally. Problems arise with letters in the encodings charset=iso-8859-1 or, for example, charset="windows-1251", I think the problem occurs in other encodings other than UTF-8. I tried to change the storage to a file and see what format the letters are stored in on the disk - everything is fine with the encoding there, but if you look through any client (Roundcube or thunderbird), I already receive the same letter with a broken encoding.

from client

from disk

How can we reproduce the problem?

Send letter in Cyrillic to stalwartmail server from server uses windows-1251 encoding

Version

v0.9.x

What database are you using?

RocksDB

What blob storage are you using?

RocksDB

Where is your directory located?

Internal

What operating system are you using?

Linux

Relevant log output

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

[mdecimus]

Is your mail client using the 8BITMIME extension when sending the message?

[mdecimus]

It will break the encoding if the 8BITMIME extension is not used. Try setting the log level to trace and check the SMTP transaction when the client sends the message.

[DSpeichert]

@mdecimus we have a similar issue that applies to messages encoded iso-8859-2.

I'm still verifying the facts. Issue maybe only applies to messages transferred over imapsync from another server. Messages that were received by stalwart seem to be fine even using encoding other than UTF-8.

EDIT: apparently it's happening for new messages as well.