add R flag (don't prune route-addrs); improve diagnostic checks

generalize read timeout

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

move the meta-characters from C0 into C1 space

clean up log levels; allow IDA-style split header/envelope rewriting;
extend arpatounix with more zones (but is this even needed?)

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

System 5 compatibility, misc fixes

implement arpatounix; log more info; allow nested $?...$|...$.;
POSIX compatibility; handle SMTP MAIL command errors properly;
do early diagnosis of .cf errors; adjust checkpointing; misc bugs

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

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

Release 6

allow I option to arbitrarily set and clear resolver options

restore # as comment symbol in .forward/:include:; extend -p flag;
remove = option (use V instead)

J option sets "search path" for .forward

dynamically allocate header fields (and more....); miscellaneous
cleanup (mostly comments)

don't auto-initialize host map if user has already done it

allow specification of arbitrary string on successful db match

finish support for generalized maps

(partially) ANSI-fy it

fix a variety of small bugs noticed by bcx

miscellaneous bug fixes from Bryan Costales and Craig Lant

portability changes

option E has to be in a safe environment; otherwise you could point
at a file that you can't otherwise read

OE is the same as omitting it

finish uid_t/gid_t conversion; allow locally customized message for
prepending to all error returns