[ale] Bellsouth vs. sendmail "smart host"

[Steve Tynor]

All,

Some time saturday afternoon, my outgoing mail stopped working.  I'm
running sendmail 8.11.6 (stock redhat 7.3) configured with
mail.bellsouth.net as the "DS" smart host.  This has worked for months
without any problems, but suddenly on saturday, Bellsouth started
rejecting my attempt to relay:

| 550 .net 022: Your current IP address is not allowed to relay to foo.com Solution: Connect using BellSouth Internet Service.

Replace any domain we try to send mail to for foo.com

If I try the same from Outlook on a winders box, it works ok, so I think
the msg is misleading (i.e. it's not mapping our _IP_ to a
rejected-relay list).

I've debugged by telnet'ing to port 25 at mail.bellsouth.com.  I can
send mail by hand like that all day.  Looking at "mail -v" output, I see
that it claims to be using mx00.mail.bellsouth.net -- NOT
mail.bellsouth.net as is specified in sendmail.cf.

| [root at gromit etc]# mail -v foo at foo.com
| Subject:
| Cc:
| ^D
| foo at foo.com... Connecting to mx00.mail.bellsouth.net. via relay...
| 220 mail.bellsouth.net ESMTP server (InterMail vM.5.01.05.27 201-253-122-126-127-20021220) ready Sat, 28 Jun 2003 20:11:08 -0400

If I telnet to mx01.mail.bellsouth.net, I can reproduce the errors!

Aha!  I'm talking to the wrong relay server.

But!?

Why is sendmail using mx00 (or sometimes mx01) instead of
mail.bellsouth.net as we've specified in sendmail.cf.  dig shows mx00
and mx01 as the MX records for the bellsouth.net domain.  But why the
heck would sendmail be using MX records for a relay?  I checked
reverse-ip's and you can't get mx00 from mail.bellsouth.net or vice
versa by resolving reverse ip's.

I've grep'd everything under /etc and the only line containing the
string bellsouth is the DSmail.bellsouth.net line in /etc/sendmail.cf.

I'm stumped.

Here's the snippet that corresponds to a failed attempt to mail to
tynor at foo.com with DS set to "mail.bellsouth.net".  I have no idea were
those two IP addresses come from (192.* and 172.*).  I don't see those
in the bellsouth.net zone info from dig.  I don't use the 192.* or 172.*
subnets internally (our internal green net is 10.*):

Jun 29 09:48:57 gromit sendmail[30219]: gethostbyaddr(192.168.127.1) failed: 1
Jun 29 09:48:57 gromit sendmail[30219]: gethostbyaddr(172.16.76.1) failed: 1
Jun 29 09:48:57 gromit sendmail[30219]: h5TDmvb30219: from=tynor, size=48, class=0, nrcpts=1, msgid=<200306291348.h5TDmvb30219 at gromit.iintiip.com>, relay=tynor at localhost
Jun 29 09:48:57 gromit sendmail[30219]: h5TDmvb30219: to=tynor at foo.com, ctladdr=tynor (501/100), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30048, relay=mx00.mail.bellsouth.net. [205.152.59.32], dsn=5.1.1, stat=User unknown


I've googled, and searched the Ale archives to no avail.  The Bellsouth
support folk refuse to consider this their problem since it works OK
from M$ Outlook.  Thanks for any help!

Steve
steve at iintiip.com
http://www.iintiip.com/surplus

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