- Plesk for Linux
What hostname should be set if the server is behind NAT, public FQDN or private FQDN?
It is recommended to use public FQDN. However, if for some reason this is not possible (due to some network/virtualization configurations), this is safe to have private FQDN as Plesk server hostname, in most cases it will work without issues.
The only issue could occur while sending mail. As a default, the hostname is being used by SMTP server. Some antispam tools on recepient side could try to verify the hostname and if it is not possible, reject mail message.
For this case, create A, PTR record for public FQDN on registrar's side to make the server accessible through some public FQDN. Specify this public FQDN as a value for