Relay Station Name Macro (R)

Relay Station Name Macro (R)

The R macro defines the station name (or an alias) used by all stations that act as relay stations. Relay stations are forwarders to known internal domains and are defined by the use of this relay station name as their station name or alias. This macro comes preconfigured as "relay," a name that is strongly suggested.

Do not leave this macro blank, even if your network has no relay stations configured.
Mail relay stations provide an alternative to an MX scheme, and can also be useful as an emergency backup to the use of MX records for internal mail routing.