RSA server certificate CommonName (CN) `localhost' does NOT match server name!?

[v8production]

Hello everyone,

As the title suggested:

RSA server certificate CommonName (CN) `localhost' does NOT match server name!?

I saw this line from the full error log of an user. Is there anything I could fix? The setting of the DNS was done by my colleague and he has resigned. Right now I am not able to receive email but able to send.

Thank you very much.

 

[zEitEr]

Hello,

If it's about hostname, then install a valid for it. Search the forums and help pages for more details about letsencrypt.

If it's about an user domain without SSL cert or cert without mail subdomain or with, then search the forums and hep pages for more details about mail_sni.