1754137 - reseting imap connection after server's Hello!

Status: RESOLVED INCOMPLETE

(MailNews Core :: Networking: IMAP, defect)

Description

[Alexander]

Attachment: xxx.dump

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:96.0) Gecko/20100101 Firefox/96.0

Steps to reproduce:

windows 10 21H1
thunderbird 91.5.1 x64

it started suddenly on February 4, I don’t know what could have caused it -
Thunderbird stopped syncing imap folders.
I took a tcpdump on the server, it's in the attachment.
after the server response Hello! thunderbird reset connection.
I tried in parallel on the same computer Claws Mail client and it works fine.

I tried various manipulations, for example, disabled ipv6 on the interface and Thunderbird suddenly started working normally, but later the situation came back.
Then I turned off the antivirus - it started working normaly, but then the same problem again.

I completely deleted the Thunderbird folders from the user profile and set up the mailbox again - already at the stage of connecting the mail account, Thunderbird could not establish a connection

and again - Claws Mail client works perfectly all the time in parallel on the same computer

Actual results:

thunderbird reset imap connection

Expected results:

thunderbird must respond to imap server and continue normal imap session

Comment 1

[Alexander]

update #1:

I've downloaded Thunderbird Portable 91.5.1 from site "portableapps dot com" to the same computer and it works perfectly.

I've totaly removed Thunderbird and its folders in user profile Appdata\Roaming and Appdata\Local, install Thunderbird 91.5.1 x64 downloaded from https://www.thunderbird.net/ and it doesnt work - same situation - already at the stage of setting up mail account, Thunderbird could not establish a connection (tcpdum shows same reset packet)

I close installed Thunderbird, open Thunderbird Portable and it works perfectly.

Comment 2

[Wayne Mery (:wsmwk)]

Alexander, does this still reproduce for you?

Comment 3

[Wayne Mery (:wsmwk)]

More information is needed.