This directory contains the repository of all versions of BSD UNIX Sendmail
that have ever been shipped with BSD UNIX releases. It includes versions 4.12,
5.52, 5.60, 5.61, 5.61.1.1, 5.64, and 5.67. 5.52 is really 5.52, even though
its src/Version.c (and hence the SMTP greeting) says 5.51 (whoever built it
forgot to update src/Version.c).