For the past few days, the Avast Firewall has repeatedly been preventing Thunderbird from connecting to mail servers via POP, IMAP, or SMTP. Thunderbird keeps trying to connect for a very long time and finally gives up: “access denied”.
Actually, Avast should have “smartly” detected the program and let it through. I even manually added Thunderbird.exe to the list of trusted applications, but the only result is that it no longer appears in the firewall log – but it’s still being blocked. As soon as I disable the Avast firewall, Thunderbird connects immediately.
When I restart Windows, it usually works again – at first. But the problem can resurface at the next day.
I’m using the latest Avast build, 26.5.10994.984 (I had the same problem with the previous version as well).
I hadn’t experienced these issues either, until just this week. When Avast acts up, neither POP, IMAP, nor SMTP works. But there are no noticeable issues in the browser, so it took me quite a bit of troubleshooting to identify the Avast firewall as the cause of the problems.
Could it be because I customized the Avast installation a week ago using the regular setup options dialog? I removed the “Fraud Protection” feature that had been installed without my consent. However, that shouldn’t affect the firewall module.
Have you got the Firewall set to use Smart Mode and Smart Mode + Notifications as in my image.
Can you outline the steps you took
Digging through the Avast Settings as I don’t see anything about Fraud Protection and a google search on this generally indicates it is a business protection level.
Further digging would indicate that this is an Avast One feature, but it isn’t posted in the Avast One sub-forum.
I don’t know what those features are called in the English version. With its nested features and modules, Avast has become a very confusing maze of functions.
Here is a screenshot of the dialog showing what is currently installed. I uninstalled the “URL Wächter” (“URL Watcher”?) option a week ago.
What you uninstalled is the Web Shield component which is there in both products. Notably it is unrelated to the to the Firewall.
I’m a little surprised that it had any effect on the Firewall component.
That is what I thought you were disabling. As you have effectively disabled the protection given by the Web Shield (and the Mail Shield, in your image) when browsing and not your email as such. That may be why you aren’t getting any alerts, but I guess there an interaction if it is Web Mail that you are downloading.
