The nrcpts= syslog equate shows the number of recipients after all aliasing has been performed. If the original message was addressed to root, and if root was aliased like this:

root: bob, hans

and if bob's ~/.forward file contained this:

\bob
|"/usr/ucb/vacation bob"

the nrcpts= syslog equate would show three recipients.

Note that nrcpts= is included only with the sender record and that record is emitted when the message is first processed. Any later changes in aliasing that might happen while the message is queued are not reported. Aliasing on remote machines (as would be the case with exploder mailing lists) is also not reported for obvious reasons.