2065024 - Gmail IMAP extremely slow; XOAUTH2 authentication can take ~60 seconds and Thunderbird reports authentication failure

Status: RESOLVED DUPLICATE of bug 2063816

(Thunderbird :: Untriaged, defect)

Description

[arthemesia]

Attachment: thunderbird-imap-bugzilla-SAFE.log

User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/151.0.0.0 Safari/537.36

Steps to reproduce:

Configure a Gmail account in Thunderbird 153.0.2 using IMAP, SSL/TLS and OAuth2.
Start Thunderbird and allow it to check and synchronize the Gmail account.
Wait for new messages to download or open a newly received message.
The issue also occurs with a completely fresh Thunderbird profile.

Other IMAP accounts (Zoho and Outlook.com) work normally in the same Thunderbird profile and on the same network connection.

Actual results:

Gmail IMAP is extremely slow. New message headers may appear, but message bodies can take several minutes to load. On startup, new Gmail messages have sometimes taken approximately 20 minutes to appear.

Thunderbird intermittently displays:

Authentication failure while connecting to server imap.gmail.com

However, IMAP logging shows that the XOAUTH2 authentication eventually succeeds. In one captured session Thunderbird sent the XOAUTH2 authentication at 06:18:32.709 UTC and Gmail responded with authenticated (Success) at 06:19:31.166 UTC — a delay of approximately 58 seconds.

Subsequent IMAP operations are also unusually slow. NAMESPACE, COMPRESS, ID, ENABLE, XLIST and LIST commands took several seconds each.

During an initial Gmail folder synchronization, Thunderbird transferred only approximately 5 MB in 30 minutes.

A direct TLS connection to imap.gmail.com:993 using openssl s_client succeeds immediately and certificate verification is OK.

The same Gmail symptoms previously occurred in Betterbird. Moving to Thunderbird and creating a completely new profile did not resolve the Gmail problem.

Expected results:

Gmail IMAP authentication and synchronization should complete within a normal amount of time. New messages and message bodies should download promptly.

Thunderbird should also not report an authentication failure when XOAUTH2 authentication subsequently succeeds.

Comment 1

[Magnus Melin [:mkmelin]]

Maybe bug 2063816

Comment 2

[arthemesia]

Sorry, didn't notice that, but yes, sounds like the exact same problem.