Greg-- Here is the abstract. My network addresses are ostensibly "eric@Berkeley.ARPA" (host 10.2.0.78) and ucbvax!eric; the address "eric@UCB-ARPA.ARPA" may be more inclined to get to me. SENDMAIL -- An Internetwork Mail Router Eric Allman Britton-Lee, Inc. Routing mail through a heterogenous internet presents many new problems. Among the worst of these is that of address mapping. Historically, this has been handled on an ad hoc basis. However, this approach has become unmanageable as internets grow. Sendmail acts a unified "post office" to which all mail can be submitted. Address interpretation is controlled by a production system, which can parse both old and new format addresses. The new format is "domain-based", a flexible technique that can handle many common situations. Sendmail is not intended to perform user interface functions. Sendmail will replace delivermail in the Berkeley 4.2 distribution. Several major hosts are now or will soon be running sendmail. This change will affect any users that route mail through a sendmail gateway. The changes that will be user visible will be discussed.