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Sending email messages fails suddenly

  • 2 replies
  • 1 has this problem
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  • Last reply by admin293

admin293
admin293
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Hello.

I have been using Thunderbird for many years. i have it installed on four laptops and up until today it was working fine. On one of my laptops, the one I use most often, I can no longer send emails. The message fails at "Assembling Message". The operating system is the latest version of Windows 10.

This started suddenly today after sending about 50 emails. It does not affect any other laptop with Thunderbird.

I can receive emails fine. There is no anti-virus software on this machine.

What I have done to fix it:

Uninstalled Thunderbird and reinstalled. No effect Uninstalled Thunderbird, deleted Program Files and Appdata directories, reinstalled. No effect Uninstalled Thunderbird, copied known working directories from another machine, reinstalled. No effect.

I installed Mailbird and found it works fine for both sending and receiving.

So that leaves out the firewall, database corruption, blocks from my ISP or mail provider (which are different). The only remaining point of failure is damage to the registry. The uninstalls should have fixed that.

Any ideas?

Thanks.

Hello. I have been using Thunderbird for many years. i have it installed on four laptops and up until today it was working fine. On one of my laptops, the one I use most often, I can no longer send emails. The message fails at "Assembling Message". The operating system is the latest version of Windows 10. This started suddenly today after sending about 50 emails. It does not affect any other laptop with Thunderbird. I can receive emails fine. There is no anti-virus software on this machine. What I have done to fix it: Uninstalled Thunderbird and reinstalled. No effect Uninstalled Thunderbird, deleted Program Files and Appdata directories, reinstalled. No effect Uninstalled Thunderbird, copied known working directories from another machine, reinstalled. No effect. I installed Mailbird and found it works fine for both sending and receiving. So that leaves out the firewall, database corruption, blocks from my ISP or mail provider (which are different). The only remaining point of failure is damage to the registry. The uninstalls should have fixed that. Any ideas? Thanks.

All Replies (2)

Stans
Stans
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Windows 10 has an inbuilt antivirus, called Windows Defender Antivirus. Which version of Tbird is it?

admin293
admin293 Question owner
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Thunderbird is version 78.3.2. Windows Defender Antivirus is turned off. No other antivirus software or malwware scanner is active. i added outbound rules to Windows Firewall to open ports 25, 465, and 587 to allow everything as a sledgehammer approach. I'm using port 465. Mailbird works, emClient works. Thunderbird worked for many years until yesterday afternoon. Thunderbird still works fine on my backup machines on the same network.

It's a connection issue to my server on this one machine. Thunderbird also cannot save Drafts. I set everything to local folders, including Drafts to the local Trash folder and that still didn't fix it.