Hi Basically I was getting an error with dovecot certificates, not being fully recognised. This was causing issues with clients not being able to verify properly against the certificates for their mail. In the dovecot.conf file, it seems that virtualmin is placing entries under the “!include_try local.conf” section. Basically this points to certs for individual virtual servers that are created. What is happening is that the cert is pointing to: /home/username/ssl.cert, whereas it should be pointing to /home/username/ssl.combined. If this is changed, then there should be no issues with the certs anymore.
Please check into, and adjust code accordingly.