Unable to send or receive messages although connects to server OK
I have a weird issue on a new install of Thunderbird on Windows 7.
Thunderbird connects OK to my mail server and says e.g 'Downloading Message 1 of 2' etc. However, the messages are not downloaded. No error message is shown, but no emails.... Server settings are definitely correct as I have duplicated them on another PC which works fine.
Sending an outgoing mail fails with the message 'The message could not be sent because the connection to Outgoing server (SMTP) [myserver.net] was lost in the middle of the transaction. Try again.'.
This suggests some sort of network issue. Reinstalling the network adaptor does not fix the issue. PC connects to internet with no issue.
If I boot Windows in Safe Mode then Thunderbird does work, both send and receive.
Just to be clear, it is a fresh install of Thunderbird with no add ons.
Modified by sb65
All Replies (5)
Have you installed an anti virus other than defender. It sounds like you have.
AVG is running, but I've never had any issues with AVG and Thunderbird before?
Hmm. Temporarily disabling AVG does fix the issue. However, I have at least three other PCs running Thunderbird and AVG with no issues. Any suggestions? Reinstall AVG?
Looks like this may be an AVG issue: https://support.avg.com/answers?id=9060N000000LmdfQAC
Personally I question the need to even scan incoming and outgoing mail. One of the reasons I dumped AVG probably 10-15 years ago was because it got excited about disabling it's mail shield and complained about it vigorously.
With the allow anti virus to scan emails in Thunderbird's options enabled every email "File" is made available for scanning by being saved in the temp folder before being incorporated into Thunderbird. So incoming email scanning is not a "thing". It is however a problem because it regularly breaks.
Outgoing scanning is a complete waste of time. If the AV can't find malware on your computer it is not suddenly going to find it in the outgoing messages. But it gives an opportunity to stick an add into the mail saying it is scanned by brand whatever.
Even less useful and full of issues is the scanning of stored mail. IT is a completely safe text file, but AV companies scan it over and over. Again causing issues with file contention and speed. Sp much s we recommend creating an exception in anti virus for the Thunderbird mail folders and the global message index.