Are you using Bitdefender?

I have the same issue. But I notice that with IMAP there is no issue, only with the POP3 I have this issue since 11/08/2025. I take my emails in from Telenet (Belgium provider). I have put in the first mail that was not OK in POP3, you can also see it is OK from IMAP.

Hi Ed, I am using Bitdefender.

Try this:

Open Bitdefender

- go to Protection > Online Threat Prevention > Encrypted web scan > toggle it to Off

- restart TB

It may or may not work; the problem has been reported and is [being investigated](https://community.bitdefender.com/fr/discussion/comment/356137?utm_source=community-share#Comment_356137).

Hi, I deleted my pop email account and recreated it. surprise it worked, mails came in correctly....... for a while, now it is again the same problem. Very strange.

It is very strange : some rare mails came correctly, some not without any explanation to this !! It seems that there is an issue with the "Orange security suite" : on the Orange forum a lot of customers have the same issue without any solution for the moment !

I use Windows 10 / Bitdefender Internet Security / Thunderbird. I have the same problem: emails received have no subject, no sender and the content is in source code. So they are unusable.

- For some users, the following intervention in Bitdefender solves the problem, for others it does not. In Bitdefender: "Online Threat Prevention": settings => disable "Encrypted Web Scanning" This does not work for me.

- The solution I found in my Thunderbird account settings: For each email account: => "Server Settings": connection security: select "SSL/TLS" Exit Thunderbird and retstart. This solves the problem for me.

This worked for me : go to Protection > Online Threat Prevention > Encrypted web scan > toggle it to Off

For each email account: This was already set => "Server Settings": connection security: select "SSL/TLS"

Solution update posted at 8:48 Eastern time (12:48 UTC) Thursday by Alexlandru_BD, an admin at bitdefender, "The developers reverted the changes made in the last signature update and this should do the trick until a permanent fix is deployed. Just click on update in systray and reboot once completed. But keep in mind this change is being rolled out gradually, so it may not reach everyone at the same time.." More details at https://www.reddit.com/r/Thunderbird/comments/1mo693n/comment/n8ammvq/