After having blocked my output mail account for several hours because of accidental permanent rejection of my TLS certificate I noticed evolution has no option reallow a certificate. 

It would be nice to have a list at the certificates where the rejected ones are listed as well. It happens very easy to reject a cert and it took me many hours to find the "camel_cert" directory to delete the entry. Normal users might have just deactivated TLS or Encryption which would have solved the problem easily. 

Maybe at first it would help to extend the message ("... certificate rejected") you get with a "to accept the certificate click here".