PMDF System Manager's Guide

As background regarding the concept of subaddresses, the PMDF local and msgstore channels interpret a + character in the local portion of an address (the mailbox portion) specially: in an address of the form name+subaddress@domain PMDF considers the portion of the mailbox after the plus character a subaddress. The msgstore channel when delivering to a popstore account and the local channel treat a subaddress as additional cosmetic information and actually deliver to the account name, without regard to the subaddress; the msgstore channel when delivering to a PMDF MessageStore account interprets the subaddress as the folder name to which to deliver.

Subaddresses also affect the lookup of aliases by the local channel (that is, the local channel on OpenVMS or UNIX, or the msgstore channel on NT) and the lookup of aliases by any channel marked with the aliaslocal keyword, and the lookup of mailboxes by the directory channel. The exact handling of subaddresses for such matching is configurable: when comparing an address against an entry, PMDF always first checks the entire mailbox including the subaddress for an exact match; whether or not PMDF performs additional checks after that is configurable.

Note that the msgstore channel behaviors of ignoring subaddresses as far as actually delivering to a popstore account and interpreting subaddresses as folder names when delivering to a MessageStore account are true on all platforms. But it is only on NT platforms that MessageStore and popstore addresses are considered local, hence by default compared against the alias file and alias database. On all platforms other than NT, you must use the aliaslocal keyword on the msgstore channel if you want to compare addresses against the alias file and alias database. Hence the subaddress* keywords are always relevant for the msgstore channel on NT, but on other platforms are relevant only if the msgstore channel is marked with the aliaslocal keyword.

The subaddressexact keyword instructs PMDF to perform no special subaddress handling during entry matching; the entire mailbox, including the subaddress, must match an entry in order for the alias to be considered to match. No additional comparisons (in particular, no wildcarded comparisons or comparisons with the subaddress removed) will be performed. The subaddresswild keyword instructs PMDF that after looking for an exact match including the entire subaddress, PMDF should next look for an entry of the form name+*. The subaddressrelaxed keyword instructs PMDF that after looking for an exact match and then a match of the form name+*, that PMDF should make one additional check for a match on just the name portion. With subaddressrelaxed, an alias entry of the form

name: newname+*

will match either name or name+subaddress, transforming a plain name to newname, and transforming name+subaddress to newname+subaddress. subaddressrelaxed is the default.

Thus the subaddresswild keyword or the subaddressrelaxed keyword may be useful when aliases or a directory channel are in use yet users want to receive mail addressed using arbitrary subaddresses. These keywords obviate the need for a separate entry for every single subaddress variant on an address.

Note that these keywords only make sense for the local channel (that is, the l channel on OpenVMS or UNIX, or the msgstore channel on NT) and the directory channel, or any channel marked with the aliaslocal keyword.