public versus private
- Viktor Dukhovni:
> All delivery agents are "private" while "pickup", "qmgr", "flush"This was changed from "private" into "public", so that postdrop
> and "showq" are "public" to support postdrop(1) and postqueue(1)
> and their sendmail(1) interfaces. Almost everything else is private,
> except for cleanup(8) which AFAIK is public only for historical
could directly submit mail into cleanup, using the maildrop directory
only as a fall-back mechanism in case cleanup transaction failed.
Recovering from all possible failure modes is complicated and I did
not get around to write that code (and there are few people who I
would trust to write it).