Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP)
1. I have three different outgoing SMTP accounts (to 3 different providers) 2. I can receive messages from all 3 accounts. 3. I can send very short messages from all 3 accounts. 4. Any message that is a reply or longer than few lines fails with the below error message for all 3 accounts: "Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP) " Ping works fine. 5. I use Thunderbird 45.3.0 on Windows 10 (64 bit); No standalone anti-virus, just regular Windows Defender. I tried everything, including reinstalling Thunderbird, removing/adding back accounts, compressed folders, removed all add-ons including Lightening, .
I tried to google and read knowledge base, but could not find working solution. Hope someone can help. My Thunderbird basically became unusable for sending emails :(
Thank you, Karine
Chosen solution
christ1 said
Try to 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 safe mode. - https://support.mozilla.org/kb/safe-mode Does the problem go away?
Thank you very much for your advise!
It seems to help. I was able to send at least 7 messages that did not go through before. Hope the problem does not return.
Karina
All Replies (6)
Try to 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 safe mode. - https://support.mozilla.org/kb/safe-mode
Does the problem go away?
Chosen Solution
christ1 said
Try to 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 safe mode. - https://support.mozilla.org/kb/safe-mode Does the problem go away?
Thank you very much for your advise!
It seems to help. I was able to send at least 7 messages that did not go through before. Hope the problem does not return.
Karina
Modified by qformula
Windows safe mode disables anti-virus software, which is most likely the culprit. The following are suggestions to mitigate problems caused by anti-virus software.
Create an exception in your anti-virus software for the Thunderbird profile folder, so that the anti-virus real-time scanner will not scan it. http://kb.mozillazine.org/Profile_folder_-_Thunderbird
Don't let your anti-virus software scan incoming and outgoing messages.
Don't let your anti-virus software scan attachments.
Don't let your anti-virus software intercept your secure connection to the server.
Remove any add-ons your anti-virus software may have installed in Thunderbird.
Keep it working. http://kb.mozillazine.org/Keep_it_working_-_Thunderbird
christ1 said
Windows safe mode disables anti-virus software, which is most likely the culprit. The following are suggestions to mitigate problems caused by anti-virus software. Create an exception in your anti-virus software for the Thunderbird profile folder, so that the anti-virus real-time scanner will not scan it. http://kb.mozillazine.org/Profile_folder_-_Thunderbird Don't let your anti-virus software scan incoming and outgoing messages. Don't let your anti-virus software scan attachments. Don't let your anti-virus software intercept your secure connection to the server. Remove any add-ons your anti-virus software may have installed in Thunderbird. Keep it working. http://kb.mozillazine.org/Keep_it_working_-_Thunderbird
Thank you! Yes, to prevent future re-occurrences, I will check further into the Windows defender - that is the only anti-virus I have. After Windows 10 anniversary upgrade it might have became more strict. Thank you again for helping me to solve the issue - I can't function properly without Thunderbird! It kind of became my 'secondary' personal memory with 12 years of archives :). I got it almost on the day it was released!
I'm seeking solution to simular but different problem. On occasion, I'll get the message: "Sending of the message failed. The message could not be sent because the connection to Outgoing server (SMTP) secure164.inmotionhosting.com timed out. Try again."
My issue is not with the connection but with the loss of the message. Usually the problem with the sending failure is that I forgot to turn on my modem (or equivalent). My problem is that I don't know how to recover the message that has not been sent. When sending fails, message does not get put in the "drafts" folder as best I can tell. It also, for obvious reason, can not be found in the "sent" folder.
What does Thunderbird do with messages that can't be sent?
Michael Ernstoff in Los Angeles
WindsurferLA,
please start a new topic for your problem. https://support.mozilla.org/questions/new