syslog when low on disk space

close cached MCI connections after a fork; add p (privacy) and b
(min blocks free) options; fix selfref code; clean up $#error format

let HPUX use initgroups; -DHASINITGROUPS if you have one

fix a variety of bugs found by Eric Wassenaar <e07@nikhef.nl>

move the meta-characters from C0 into C1 space

HPUX and OSF/1 support; fix SMTP reply codes & multiple SMTP error
problem; consider cache timeout non-permanent; be more graceful on OS
failures; log forward, alias, and userdb expansions on log lev

HPUX and OSF/1 support; fix SMTP reply codes & multiple SMTP error
problem; consider cache timeout non-permanent; be more graceful on OS
failures; log forward, alias, and userdb expansions on log level 10

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fix wildcard MX handling (option W no longer needed); fix
process title when using cached connection; many minor fixes

System 5 compatibility, misc fixes

fix -e compat flag; a few compilation warnings; improve error messages

more environment problems; limit resource exhaustion; fix incorrect
name in Connection timed out message; ANSI C fixes; log message sender on
returned mail during queue run; count recipients properly

more environment problems; limit resource exhaustion; fix incorrect
name in Connection timed out message; ANSI C fixes; log message sender on
returned mail during queue run; count recipients properly; fix YP code;
diagnose "message timed out" properly

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fix problem with address delimitor inside quotes; define $k and $=k
to be the name (from the uname call)

change checkcompat() to return an exit status

MX piggybacking, based on code from John Myers@CMU; allow checkcompat
to return -1 to mean tempfail; bug fix in m_mno computation

tuning of queueing functions as recommended by John Gardiner Myers
<jgm+@CMU.EDU>; return mail headers (no body) on messages with negative
precedence; minor other bug fixes

define prog mailer by default

changes to recognize special mailer types (e.g., file) early

don't malloc before calling thaw

put return-receipt-to on a conf.c flag (but don't set it);
fix minor syslog problem

Release 6

change random constants to be #defines

add NIS map type; log message-id in same line as from logging

tweak some of the configurations to up some values

make it use varargs/stdarg and vsprintf

allow specification of arbitrary string on successful db match

finish support for generalized maps