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Thunderbird failed to assembling message

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  • 2 have this problem
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  • Last reply by Matt

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hi, running Thunderbird 60.8 latest version on win10. I receive messages as normal but i can not send messages. Thunderbird says Failed to send message and behind of this windows is a window which says Assembling message with green bar. I have 10 account in my Thunderbird and i have the same problem with all of them. ( IMAP accounts with different SMTP server and credentials). I clear Thunderbird cache, tried to reinstall Thunderbird, switch off bitdefender firewall/antivirus but no luck. Any suggestion please???

Thanks in advance

hi, running Thunderbird 60.8 latest version on win10. I receive messages as normal but i can not send messages. Thunderbird says Failed to send message and behind of this windows is a window which says Assembling message with green bar. I have 10 account in my Thunderbird and i have the same problem with all of them. ( IMAP accounts with different SMTP server and credentials). I clear Thunderbird cache, tried to reinstall Thunderbird, switch off bitdefender firewall/antivirus but no luck. Any suggestion please??? Thanks in advance

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I would suggest you try the following. Especially the windows safe mode stuff. Unfortunately when anti virus programs go to god, they often do not turn off when they say they do.:

  • Restart Thunderbird with add-ons disabled (Thunderbird Safe Mode). On the Help menu, click on "Restart with Add-ons Disabled". If Thunderbird works like normal, there is an Add-on or Theme interfering with normal operations. You will need to re-enable add-ons one at a time until you locate the offender.
  • Restart the operating system in safe mode with Networking. This loads only the very basics needed to start your computer while enabling an Internet connection. Click on your operating system for instructions on how to start in safe mode: Windows 10, Windows 8, Windows 7, Windows Vista, Windows XP, OSX
If safe mode for the operating system fixes the issue, there's other software in your computer that's causing problems. Possibilities include but not limited to: AV scanning, virus/malware, background downloads such as program updates.