A recurring argument that pops up from time to time is replacing Sendmail in the base system with something else – Postfix , qmail, or a similar product.  Licensing, complexity, or user preference usually lead to a long discussion that doesn’t change the matter.  Simon ‘corecode’ Schubert has come up with an answer: none of the above.  He’s writing a simple MTA that will handle delivery on the local machine, which is enough for a system that doesn’t handle normal mail.  For people who need more, sendmail and Postfix and others are all in pkgsrc.