in my iphone all seems to work. ...

i can not receive mails

This isn't exactly a comprehensive problem description. You'd need to provide more details about your problem. Please explain

• what you're doing,
• what happens,
• what you expect to happen.

i wanted to read my incoming emails. There were none. I closed Thb, waited 10 sec, openend Thb. Then i got 3 times a message that the certificate is not from a trusted source. see the attachments. When i go to webmail, the mail is there. But it will not arrive in Thb. And it does arrive in my iphone. So it has to do with windows and Thb. I did not change any settings in the accounts.

Later when I tried to solve the problem i took away the V in asking OCSP responderserver.. but the result stayed the same. No income mail.

Generally issues with invalid certificates are caused by antivirus programs using self signed certificates that Thunderbird simply does not support unless you manually add them and direct Thunderbird certificate manager to use them. One of the worst for this is Norton as it has a setting to scan encrypted connections and they interpret this permission for be ALL encrypted communications. Even if you disable email scanning they still scan the data stream, if not the individual emails it contains.

To follow up on Matt's post - what is your anti-virus software?

i took away the V in asking OCSP responderserver.

The problem is almost certainly not related to OCSP.

thank you all for the replies. The antivirus is Bitdefender, which works very well for me. I could not find the real reason but sometime today it all started to work. So the problem is solved, although I can not write down how or what.

Thank you all for your help!!!

You did not find the problem as you are still praising the most likely cause cause of the issues. Bitdefender is working very well for you, you think. I am almost certain that is has not been.

Here a just a few prior gems from Bitdefenders chequered past so you are not so sure next time when something stops working you look outside the application that has the problem. Generally speaking antivirus product phone home hourly these days and update. So if something suddenly stops doing what it used to do and nothing has changed the most likely thing to have changed is the antivirus product, simply by virtue of the hourly updates.

https://support.mozilla.org/en-US/questions/1288875 https://support.mozilla.org/en-US/questions/1277253 https://support.mozilla.org/en-US/questions/1098049 https://forums.mozillazine.org/viewtopic.php?f=39&t=1973177&p=10075691#p10075691 https://support.mozilla.org/en-US/questions/1280635 https://support.mozilla.org/en-US/questions/1403964