tried the support article on the subject? https://support.mozilla.org/en-US/kb/cannot-receive-messages

Hi Matt, Thanks for your response. I have followed all that I can from the link you provided. It talks about Thunderbird 78 but I think that came out in 2020, so that is a non issue. My email protocol is configured right and I turned off my Norton's firewall and that didn't help. I can see my emails by going to my web based interface so the problem is not with my provider. And my password is correct.

I have seen a variety of things happen since the update. I couldn't get my new emails and I restarted my computer and the new emails came over at one point and then that stopped. At some point in time, I had a very brief pop up that said I needed to reenter my password but that went away immediately.

What else can I try? Thanks, Kathy

YOU mentioned Norton. A cold shiver ran down my back on the very mention of the product.

I know it is a pain, but please try the operating system safe mode with networking in particular from the following.

Please also provide results for the following test on your system

1. • Does Thunderbird work as expected in Thunderbird troubleshooting mode?
   • Does Thunderbird work as expected with your OS started in safe mode with Networking. Instructions for each operating system: Windows 10/11, Windows 8, Windows 7, OSX

Ok I worked my way through the Thunderbird troubleshooting mode. I had no extensions and was set on the default theme. I noticed the cache clearing button so I did that and restarted, still no go. Then I turned off the hardware acceleration and I think that fixed the problem. So I guess I will just need to keep that turned off?

If you have Norton 360 then you need to make sure the Firewall has Thunderbird as an allowed program otherwise it will block all access. No point in disabling Norton because then your default firewall will take over and it could also be blocking access.

I use Norton 360 and never had any issue, but you must set up Thunderbird as an allowed program. If it was already set up, then exit Thunderbird. Access Firewall, block Thunderbird and ok it. Then go back into Firwall and set Thunderbird as allowed. Why do this ? Because I have discovered in the past that Norton seems to think an update in Thunderbird was a new different program and it was confused. See image below as a guide.

On another occasion, I discovered that Norton had auto switched on it's VPN which plays havoc because then you discover the servers do not like it, so they may be refusing access to server. So check for the VPN option in Norton and switch it off.

Toad-Hall Thanks for the info about Norton's. My email is working now and Thunderbird is an allowed program. However if I run into problems in the future, I will follow your suggestions. Thanks.

I tried uninstalling and reinstalling 3 times...no luck so I tried removing then adding each email account and BINGO!! Give it a go.

I tried uninstalling and reinstalling 3 times...no luck so I tried removing then adding each email account and BINGO!! Give it a go. Sorry about this double post.