PMDF System Manager's Guide

This is by far the most complex case. The actual conversion performed is channel-specific.

• If the PMDF component doing the conversion is associated with the local, l, channel the local host part of the address "@local-host" is removed and then the inverse of the conversion described in Section 18.1.2 is performed. There are three additional twists, however.
  First of all, addresses of the form A%B are converted to the form B::A and addresses of the form A!B are converted to A::B. Double %s are converted to a single percent and the ordering is left unchanged. This is done so that literal percent signs can be specified in an unquoted address. However, if the mailbox is quoted, the string is "dequoted" according to the rules of RFC 822 and the result is used without further translation. These extra twists provide support for complex DECnet MAIL routing. For example:

  NED@local-host maps to NED NED%YELLOW@local-host maps to YELLOW::NED NED%YELLOW.RED@local-host maps to YELLOW.RED::NED "YELLOW::NED"@local-host maps to YELLOW::NED "A::B::C::D"@local-host maps to A::B::C::D D%C%B%A@local-host maps to A::B::C::D G%F.E%D.C%B.A@local-host maps to B.A::D.C::F.E::G "PSI%1002::TEST"@local-host maps to PSI%1002::TEST A!B@local-host maps to A::B B!C%A maps to A::B::C C%A!B maps to A!B::C DSIN%%3784374343434 maps to DSIN%3784374343434

  
  

• If the address is associated with the DECnet MAIL-11 channel d or d_ the same operations are performed except that no "@local-host" part is removed and at signs are handled just like percent signs. For example:

  NED@node maps to NODE::NED NED%YELLOW@node maps to NODE::YELLOW::NED NED%YELLOW.RED@node maps to NODE::YELLOW.RED::NED D%C%B%A@node maps to NODE::A::B::C::D G%F.E%D.C%B.A@node maps to NODE::B.A::D.C::F.E::G "PSI%1002::TEST"@node maps to NODE::PSI%1002::TEST DSIN%%3743743@node maps to NODE::DSIN%3743743

  
  

• If the address is associated with a mail_xxx channel, the address is converted in the same way as it would be for a DECnet MAIL-11 channel, but in addition the address is prefixed with the string "xxx%". This mechanism, along with channel table rewriting, can be used to make the rewrite rules for PSImail addresses much simpler.
  
• A completely different strategy is used if the daemon keyword is specified in the definition of a mail_ channel. If daemon is specified, the official host name associated with the channel is used as a prefix and the address is enclosed in double quotes and used as a suffix. Note that the argument to the daemon keyword is significant; see Section 18.1.2 for details.
  For example, suppose the daemon keyword is applied to the mail_psi channel whose official hostname is PSI%xyz::IN%. The address user@x.y would then be converted to PSI%xyz::IN%"user@x.y". This mechanism makes it possible for PMDF to send messages to another PMDF system via any mechanism supplied by VMS MAIL.
  
• There's one final feature available --- if the channel is marked with the 733 keyword all system names are truncated at the first period that appears in their names. This makes it possible to eliminate lots of channel specific rewrite rules in some configurations. For example, if the d channel was marked as a 733 channel, the addresses shown in the second bulleted item above would be converted as follows:

  NED@node maps to NODE::NED NED%YELLOW@node maps to NODE::YELLOW::NED NED%YELLOW.RED@node maps to NODE::YELLOW::NED D%C%B%A@node maps to NODE::A::B::C::D G%F.E%D.C%B.A@node maps to NODE::B::D::F::G