PMDF also contains facilities to implement a mailer or mailer gateway of its own. A mailer is typically used to provide support for longer usernames than BITNET normally supports. Mailer gateways can also be used to provide access to local non-BITNET systems from remote BITNET sites. Systems not directly attached to BITNET cannot be entered in the BITNET routing tables and therefore cannot have a BITNET address. The only way to provide remote BITNET access to such systems is to implement a local mailer which uses information in the body of the message to route the message to its true destination.
The mailer provided by the PMDF BITNET gateway channel uses BSMTP (batch SMTP) exclusively. A mailer is really nothing more than a BSMTP processor, with the proper facilities for extracting BITNET BSMTP material from an enclosing message wrapper.
PMDF's local mailer facility is implemented as a separate channel program called BN_GATEWAY.
Setting up a local mailer is a good idea. However, it is pointless to set up a mailer without registering it, since nobody will know that it is there if it isn't registered, so registering it is also a good idea.