After an SSL certificate change on my virtual server running plesk and ubuntu I suddenly run into an email issue.

Cert Hostname DOES NOT VERIFY (mail.koemanmotoren.nl != www.koemanmotoren.nl) http://www.checktls.com/perl/TestReceiver.pl

mail: e.g. kleding@koemanmotoren.nl

Indeed this site seems to verify that the hostname is mail.koemanmotoren.nl https://www.ssllabs.com/ssltest/analyze.html?d=koemanmotoren.nl

However I have changed every single hostname I could find, while changing it in plesk or via SSH it automatically changes it anyway everywhere, but somewhere must been another hostname noted?

The certificate is purchased and verified for koemanmotoren.nl and www.koemanmotoren.nl

Source: email – TLS – Cert Hostname DOES NOT VERIFY – Stack Overflow