set group ids completely before calling programs

improve responsiveness to load average

be much less trusting about setuid in mailfile -- still works for the
.forward case because ctladdr != NULL there

improved logging (log ctladdr on recipients

fix problems causing excessive numbers of open files

allow dumping of MCI cache to syslog for debugging

fix handling of pre-parsing address errors

additional debugging information for too many open files problem

check for possibility of fdopen returning null

8.6.2: improved error return messages; better error handling on
hung connections or the name server is down; add "vendor code" on V line;
fix some X-Authentication-Warning: problems; portability fixes

8.6.1: A/UX and Encore UMAX V patches; fix to not toss error messages
too early

free message during startup so that the printed message is as
fresh as possible

be more generous at assigning the home directory to $z

improve connection caching by making [host] look like host after
hostsignature call

fix problem causing "c" option (don't connect to expensive mailers)
to be ignored in some SMTP runs.

avoid duplicate error messages

NeXT portability changes; cleanup of <sys/wait.h> assumptions

print more information on "too many hops" message

more attempts to catch bad fd 1 bug

more attempts to find the fd 1 closed error

better error messages

POSIX changes

fix missing trailing \0 problem

clean up No ! in UUCP! message

reset SmtpPhase on initial connection so messages are accurate