This is a follow up to another question I had, but its quite different so I thought I'd start a new post.
I'm trying to work out why I still get this error message when adding an email account (in this case, in Thunderbird - but I also get the problem on phones as well);
The weird thing is that if I check it on SSL-Tools.net, it looks fine:
I really don't get it - as Thunderbird shows me my certificate is expired here:
Am I missing something? Please let me know if you need any more information to help me debug. I'm not sure what would be helpful.