Hello there Sam 337. We have read your message. We try to help you.

Can you send us a picture from your Smtp input and output configurations? Port numbers? What anti virus do you guys use on your pc?

Greetings Firefox volunteer.

I use Eset Internet Security which has never had an issue with Thunderbird ever.

The POP/SMTP setting are configured automatically by Thunderbird and i have attached screenshots hopefully of the right settings

ESET might have updated, or a TB update might have created an incompatibility with ESET. Issues of this sort are common:

https://support.mozilla.org/en-US/questions/1316575

that seems to apply to gmail accounts, i dont use gmail and Eset has never had any problem before. However to test i disabled an option in TB to allow antivirus client scan incoming mail and see if that has any effect and will post the result.

hi there,

I tried disabling the option in TB to allow antivirus clients scan incoming mail and made no difference. So i tried the method sfhowes suggested by disabling and re-enabling SSL/TLS in Eset. for a while it seemed to work but alas today the failed to connect message has returned.

I dont know what else to try and TB has been so reliable till now

Exclude the TB profile folder (Help/Troubleshooting, Profile Folder, Open Folder) from ESET scanning and disable ESET scanning of secure connections.

https://support.eset.com/en/kb2769-exclude-files-or-folders-from-scanning-in-eset-windows-home-products

https://support.eset.com/en/kb6519-exclude-an-application-by-name-from-scanning-in-eset-windows-home-products

i recieved your email before making further chages no problem, I have now done as you suggestions via the links you gave me and again still intermittant....one second it work ok the next it hangs or fails...its a weird case lol sorry to be such a pest.

EDIT: i ahve disabled SSL/TLS filtering in esets web and email settings...so far TB is working

Hi again

Update: just ran TB today and even with excluding the profile folder and turning SSL/TLS off in Eset the failed message still appears but if i click get messages it will sometimes work or continues to say "failed to connect to server"

Hi

I did a fresh install of Windows 10 and set up eset with the settings ive always had, This time i looked at Malwarebytes Anti-malware. There is an option called Penetration Testing which is described as " Enabling this setting provides aggressive blocking capabilities for Exploit Protection but may potentially result in false-positives or other application conflicts"

So im wondering if this is interfering with Eset and TB's latest updates. This setting is currently disabled and so far no issues with TB.

Hope this helps others

If you have two or more security apps providing real-time background scanning simultaneously, conflicts are probably more likely. I would keep the ESET background scan, with the above-stated exclusions, and reserve Malwarebytes for periodic manual scans.

The exclusions method did not work or make any difference...I have always ran both programs for years and never had any problems. The only difference is the Penetration Testing has been disabled and so far no issues

I understand the exclusion doesn't appear to affect your connection issue, but if ESET at some point declares it has found an infected message, false-positive or otherwise, it may very well quarantine the entire folder, given that TB stores messages in a single mbox file, not separate files.

well all i know is its working so im happy. Thanks all for the help

As an addendum, I can assure you ESET does cause troubles at times. My experience in December 20 with it is here https://thunderbirdtweaks.blogspot.com/2020/12/eset-stopped-me-getting-mail.html No software is above messing up, but security software is so tightly integrated to the operating system that is is more susceptible than most.