[Mimedefang] Odd reject message

[mimedefang at jameswcurtis.com]

I have a sender who is getting blocked when trying to send through my server. 
His mail server is 203.34.45.193, but when he sends, he gets a reject showing
24.61.132.169.  To complicate matters, I only use two dsbl's (spamcop and
njabl) and neither of those IP's are on the blacklists I use.  Any help?

The info from maillog:

Oct  6 19:51:50 mg1 sendmail[8705]: ruleset=check_relay, arg1=mail.austmg.com,
arg2=203.34.45.193, relay=mail.austmg.com [203.34.45.193], reject=553 5.3.0
24.61.132.169 REJECT
Oct  6 21:01:04 mg1 sendmail[15400]: ruleset=check_relay, arg1=mail.austmg.com,
arg2=203.34.45.193, relay=mail.austmg.com [203.34.45.193], reject=553 5.3.0
24.61.132.169 REJECT
Oct  6 21:09:22 mg1 sendmail[15957]: ruleset=check_relay, arg1=mail.austmg.com,
arg2=203.34.45.193, relay=mail.austmg.com [203.34.45.193], reject=553 5.3.0
24.61.132.169 REJECT

Relevant section from sendmail.mc

FEATURE(`enhdnsbl', `bl.spamcop.net', `"Spam blocked see:
http://spamcop.net/bl.shtml?"$&{client_addr}', `t')dnl
FEATURE(dnsbl,`dnsbl.njabl.org',`Message from $&{client_addr} rejected - see
http://njabl.org/lookup?$&{client_addr}')dnl

And I have several IP's in my access file, but those are not.



----------------------------------------------------------------
This message was sent using IMP, the Internet Messaging Program.