Unexpected item UTF error

Hello

I am using Axigen docker image for my emails.

|Operating system: |Linux/x64|
|Current Server version: |10.4.0-beta13|

But when I used thunderbird as a client program, I got an error message as below.

Error: Unexpected item UTF

So I checked the log files when I set the log level to Protocol communication, and I found the related logs below.

2022-07-30 15:45:38 +0000 16 1f0506565ea7 IMAP:0000111A: << 87 ENABLE UTF8=ACCEPT\r\n
2022-07-30 15:45:38 +0000 16 1f0506565ea7 IMAP:00001119: << 87 ENABLE UTF8=ACCEPT\r\n
2022-07-30 15:45:38 +0000 16 1f0506565ea7 IMAP:0000111A: >> 87 BAD Error: Unexpected item UTF
2022-07-30 15:45:38 +0000 16 1f0506565ea7 IMAP:00001119: >> 87 BAD Error: Unexpected item UTF

How can I solve this issue?

Yours sincerely

Hello,

Please enter TB config editor and set mail.server.default.allow_utf8_accept to false (default value: true).

HTH,
Ioan

Thank you for your reply :slight_smile:

I’ve downgraded the axigen docker image - 10.3.3.1 - and it works fine. I will upgrade the image if the beta tag is removed.

Thanks again.

Yours sincerely

The problem still exists in the X4 version now downloadable from the main website.

Whilst technically thunderbird shouldn’t be attempting ENABLE UTF8=ACCEPT unless UTF8=ACCEPT is declared the IMAP capabilities, the Axigen IMAP implementation in X4 is also at fault; RFC5161 states that:

  • If the argument is not an extension known to the server, the server
    MUST ignore the argument.

  • If the argument is an extension known to the server, and it is not
    specifically permitted to be enabled using ENABLE, the server MUST
    ignore the argument. (Note that knowing about an extension doesn’t
    necessarily imply supporting that extension.)

By returning an error rather than ignoring ENABLE UTF8=ACCEPT the X4 IMAP service is not compliant with the spec - whereas the X3 service is.

Matthew

Hello,

Thank you for the report. This behavior was reported internally and a fix will be developed. Until the fix is available, the above mentioned workaround can be used.

Best regards,
Paul