Quoting Brian (lxy at cloudnet.com):
> My first reaction too, but since I do have friends that use Windows and
> now that linux using qwest.net users are forced to use MSN there you have
> it. :-(

Switch to a linux-friendly ISP. :-)

> > Are you doing relaying via MX?
>  What does this feature do? 

relay_based_on_MX
                Turns on the ability to allow relaying based on the MX
                records of the host portion of an incoming recipient; that
                is, if an MX record for host foo.com points to your site,
                you will accept and relay mail addressed to foo.com.  See
                description below for more information before using this
                feature.  Also, see the KNOWNBUGS entry regarding bestmx
                map lookups.

Make sure your .cf is up to date with your .mc?

I also found around the 8.9 series that a certain order of the .mc entries
needed to happen. For instance, defines must come before other things because
they 'active' features.

I don't know if this was a bug or what, but this is my order:

includes
defines
MAILERs
MASQs
FEATUREs

So more things around and rebuild your .cf

I also cannot recommend this enough. Activate MAPS, if not for your users then
for my users :-)

FEATURE(dnsbl, `rbl.maps.vix.com', `Mail from $&{client_addr} Rejected - see
http://www.mail-abuse.org/rbl/')dnl
FEATURE(dnsbl, `dialups.mail-abuse.org', `Dialup - see
http://www.mail-abuse.org/dul/')dnl
FEATURE(dnsbl, `relays.mail-abuse.org', `Open spam relay at $&{client_addr} -
see http://www.mail-abuse.org/rss/')dnl
FEATURE(`delay_checks')dnl

Also, so some security be obscurity and prevent user harvesting:

define(`confPRIVACY_FLAGS',`goaway')dnl
define(`confSMTP_LOGIN_MSG', `$j server ready at $b')dnl

Or, just grab Real Time's sendmail rpm :-)


-- 
Bob Tanner <tanner at real-time.com>       | Phone : (952)943-8700
http://www.mn-linux.org                 | Fax   : (952)943-8500
Key fingerprint =  6C E9 51 4F D5 3E 4C 66 62 A9 10 E5 35 85 39 D9