Type: yes or no
Default: no

Description: Use this option to add a Fully Qualified Domain Name (FQDN) instead of a short hostname. You can specify this option either globally or per-source. The local setting of the source overrides the global option if available.

TIP: Set use-fqdn() to yes if you want to use the custom-domain() global option.

NOTE: This option has no effect if the keep-hostname() option is enabled (keep-hostname(yes)) and the message contains a hostname.