** mailer flags for sendmail 8.X **
a	run Extended SMTP protocol
A	user can be LHS of an alias (since V6)
b	ensure blank line at end of message
c	don't include comment part of address
C	make addresses canonical "u@dom"
d	never angle bracket envelope route-addrs (since V6)
D	CF: include Date:
e	it costs to use this mailer....
E	escape From lines to >From
f	mailer takes picky -f flag
F	CF: include From: or Resent-From:
g	sender of errors should be $g
h	preserve host case distinction
H	MAIL11V3: preview headers
i	do udbsender rewriting on envelope (since V6)
I	SMTP to another sendmail site
j	do udbsender rewriting on recipient lines (since V6)
k	don't check for loops in HELO command (since V6)
K	CHUNKING: reserved for future use
l	delivery is to this host
L	must enforce SMTP line limits
m	can handle multiple users at once
M	CF: include Message-Id:
n	don't insert From line
N	MAIL11V3: DATA returns multi-status
o	always run mailer as recipient (since V6)
p	use reverse-path in MAIL FROM:
P	CF: include Return-Path:
q	VRFY command returns 250 instead of 252 (since V7)
r	mailer takes picky -r flag
R	try to send on a reserved TCP port
s	strip quote chars from user/host
S	run as specific uid/gid
u	preserve user case distinction
U	this wants an ugly UUCP from line
v	add Content-Length: header (SVr4) (since V6)
V	UIUC: !-relativize all addresses
w	check for /etc/passwd entry (since V6)
x	CF: include Full-Name:
X	use hidden-dot algorithm
z	run Local Mail Transport Protocol (since V8)
0	turn off MX lookups (since V7)
1	don't send null bytes (since V7)
3	extend Q-P encoding for EBCDIC (since V6)
5	use ruleset 5 after local aliasing (since V6)
6	strip headers to 7 bits even in 8 bit path (since V7)
7	use 7-bit path
8	force "just send 8" behaviour (since V6)
9	convert 7 -> 8 bit if appropriate (since V6)
:	check for :include: files (since V6)
|	check for |program addresses (since V6)
/	check for /file addresses (since V6)
@	user can be user database key (since V6)
~	SGI: check for valid home directory (since V7)


** mailer flags for sendmail 5.X **
C	make addresses canonical "u@dom"
D	CF: include Date:
e	it costs to use this mailer....
E	escape From lines to >From
f	mailer takes picky -f flag
F	CF: include From: or Resent-From:
h	preserve host case distinction
I	SMTP to another sendmail site
l	delivery is to this host
L	must enforce SMTP line limits
m	can handle multiple users at once
M	CF: include Message-Id:
n	don't insert From line
p	use reverse-path in MAIL FROM:
P	CF: include Return-Path:
r	mailer takes picky -r flag
R	try to send on a reserved TCP port
s	strip quote chars from user/host
S	must be daemon to execute
u	preserve user case distinction
U	this wants an ugly UUCP from line
x	CF: include Full-Name:
X	use hidden-dot algorithm
