In Tools/Options/Advanced/General/Config. editor, you can try changing mailnews.tcptimeout. The default is 100 and increasing to 200 or so may help.

I did as suggested above & it did not help. It was set on 0 and I typed in 200. What do I do now ?

Well, it sometimes works. You might try a higher number, such as 250 or 300.

I tried that and it still won't send or forward a message. Can we set a time and date that we could talk on the phone ? Do you have a phone # that I could call you or a tech support ? I have talked to my Tech Support of my server {Plateautel.net) and they were unable to help me. They said I would have to speak with someone from Thunderbird. Thanks, Carla Deeds

Sometimes getting the same response from another email client proves useful. I suggest you download the trial version of Postbox (which is 90% identical to Thunderbird) and try there. My guess is you may get the same error. If so, that may get plateautel support to investigate. Those of us on this forum are just volunteers spending some free time to assist. Has this always been a problem? If so, there may be a setting or two that needs adjustment.

I have had Thunderbird for several years and never had this problem before. I just went to send a message on 9/15/22 and the problem occured. What other settings should I check to readjust ?

Ok. I will assume you raised the timeout to at least 300. This issue also surfaces from anti-virus updates. If you use an antivirus program, see if you can disable its interaction with email. That is, it is possible that a change to another program is causing this.

Abscent other ideas ...

• Start *Windows'* in safe mode with networking enabled

win10 https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode

• Still in Windows safe mode, start Thunderbird in Troubleshoot mode

https://support.mozilla.org/en-US/kb/troubleshoot-mode-thunderbird

Does problem go away?

E cleared the Safe Mode box in Boot Options. Then when I tried to forward I got the Authorization tab, I hit that then got a message saying it failed to send.

Now it does as before all this started, I have to click a tab concerning authorization certificate. Then I go back & Snd Now & it loades into my Sent Items folder as being sent but when I go to that gmail account it is not there.

David, Yes I increased the timeout to 300. I also did what Wayne suggested. You can see what happened in my response to him posted above. I use AVG Free for my anti-virus. I don't find where I can change the settings.

I found this on a separate thread: Open AVG AntiVirus --> click "Web & Email" component --> click the green slider button above "Email shield" to disable it. I don't know if that works, but it may if you can locate the component. You could also disable AVG temporarily to test the possibility that it interferes. (As an aside, I removed antivirus a couple of years ago and just run with the free antivirus that is built into Win10.)

I don't know for sure what did the trick but just now when I forwarded an email in Thunderbird to my gmail account, it went thru ! Just so you know, when I clicked the MY PROBLEM WAS SOLVED button, it showed page was not enabled.

I'm very pleased that all is working again. Thanks for sharing that.