Same issue as this? https://support.mozilla.org/en-US/questions/1400644

Yes, it appears to be the exact same issue. I can send from my outlook.office365.com account thru TB, but cannot receive any new messages. I have the exact same issue on 2 separate machines. However, no issues sending or receiving via iOS. Thanks for the reply.

As noted above, this began suddenly on 12/27/22 while attempting Thunderbird IMAP connections to an outlook.office365.com server, but only on my Windows 10 64-bit installation of Thunderbird, both 102.6 and 102.6.1. I can receive/send mail from the MS clients (outlook and mail) on my Windows machines. I have no problem with Android mail connections to the same outlook.office365.com server. My Windows Thunderbird clients continue to connect without problem to my Google IMAP accounts.

FYI, I have been running Thunderbird without problem for years, including a recent update by the outlook.office365.com server managers to use OAuth2 for authentication. I look forward to a solution to this recent problem -- it's hard to get work done without Thunderbird!

Thanks for the reply. I found this workaround:

Hello matthewab2001 note that a post from today links this very error message with the fact that the computer has dual network stack IPv4 and IPv6, work around is said to disable IPv6 in the network configuration. About your other client, it may be that its software is not even trying to use IPv6.

Complete thread: https://support.mozilla.org/en-US/questions/1400644

The following restored operation to my two systems. However, this may be a temporary fix, time will tell

Select: Tools -> Settings In FindSettings search for "Advanced Preferences" Click on "Config Editor" Click on "Show All" Scroll down to "network.dns.disableIPv6" Change setting to "True"

A belated hearty thank you for the quick response and recommended fix -- it worked perfectly!