Grey-listed message never accepted.

Well for the first time I have a message which was grey-listed which 
appears on the surface to have been properly resent but which never gets 
accepted for delivery. Here are some of the pertinent log entries:

Oct 18 10:05:01 mx01 sendmail[10534]: j9IG50bS010534: 
from=<SFERGUSON@broadmoor.com>, size=9227, class=0, nrcpts=1, 
msgid=<1B255EB9A7B2E44697FDAB7CA49558F304E458D0@exchange.penrose.local>, 
proto=ESMTP, daemon=MTA, relay=outbound.broadmoor.com [209.177.136.194] 
(may be forged)
Oct 18 10:05:02 mx01 sendmail[10534]: j9IG50bS010534: Milter: data, 
reject=451 4.2.1 mail j9IG50bS010534 from 209.177.136.194 temporary 
greylist embargoed
Oct 18 10:05:04 mx01 sendmail[10541]: j9IG52lY010541: 
from=<SFERGUSON@broadmoor.com>, size=9227, class=0, nrcpts=1, 
msgid=<1B255EB9A7B2E44697FDAB7CA49558F304E458D0@exchange.penrose.local>, 
proto=ESMTP, daemon=MTA, relay=outbound.broadmoor.com [209.177.136.194] 
(may be forged) Oct 18 10:05:05 mx01 sendmail[10541]: j9IG52lY010541: 
Milter: data, reject=451 4.2.1 mail j9IG52lY010541 from 209.177.136.194 
temporary greylist embargoed
Oct 18 10:06:08 mx01 sendmail[10637]: j9IG679Z010637: 
from=<SFERGUSON@broadmoor.com>, size=9235, class=0, nrcpts=1, 
msgid=<1B255EB9A7B2E44697FDAB7CA49558F304E458D0@exchange.penrose.local>, 
proto=ESMTP, daemon=MTA, relay=outbound.broadmoor.com [209.177.136.194] 
(may be forged)
Oct 18 10:06:11 mx01 sendmail[10637]: j9IG679Z010637: Milter: data, 
reject=451 4.2.1 mail j9IG679Z010637 from 209.177.136.194 temporary 
greylist embargoed
Oct 18 10:06:11 mx01 sendmail[10637]: j9IG679Z010637: 
to=<lindagay@sugarloaf.net>, delay=00:00:04, pri=39235, stat=mail 
j9IG679Z010637 from 209.177.136.194 temporary greylist embargoed
Oct 18 10:06:12 mx01 sendmail[10656]: j9IG6B2E010656: 
from=<SFERGUSON@broadmoor.com>, size=9235, class=0, nrcpts=1, 
msgid=<1B255EB9A7B2E44697FDAB7CA49558F304E458D0@exchange.penrose.local>, 
proto=ESMTP, daemon=MTA, relay=outbound.broadmoor.com [209.177.136.194] 
(may be forged)
Oct 18 10:06:13 mx01 sendmail[10656]: j9IG6B2E010656: Milter: data, 
reject=451 4.2.1 mail j9IG6B2E010656 from 209.177.136.194 temporary 
greylist embargoed
Oct 18 10:06:13 mx01 sendmail[10656]: j9IG6B2E010656: 
to=<lindagay@sugarloaf.net>, delay=00:00:02, pri=39235, stat=mail 
j9IG6B2E010656 from 209.177.136.194 temporary greylist embargoed
Oct 18 10:07:13 mx01 sendmail[10725]: j9IG7D7Y010725: 
from=<SFERGUSON@broadmoor.com>, size=9235, class=0, nrcpts=1, 
msgid=<1B255EB9A7B2E44697FDAB7CA49558F304E458D0@exchange.penrose.local>, 
proto=ESMTP, daemon=MTA, relay=outbound.broadmoor.com [209.177.136.194] 
(may be forged)
Oct 18 10:07:14 mx01 sendmail[10725]: j9IG7D7Y010725: Milter: data, 
reject=451 4.2.1 mail j9IG7D7Y010725 from 209.177.136.194 temporary 
greylist embargoed
Oct 18 10:07:14 mx01 sendmail[10725]: j9IG7D7Y010725: 
to=<lindagay@sugarloaf.net>, delay=00:00:01, pri=39235, stat=mail 
j9IG7D7Y010725 from 209.177.136.194 temporary greylist embargoed
Oct 18 10:07:15 mx01 sendmail[10729]: j9IG7FxV010729: 
from=<SFERGUSON@broadmoor.com>, size=9235, class=0, nrcpts=1, 
msgid=<1B255EB9A7B2E44697FDAB7CA49558F304E458D0@exchange.penrose.local>, 
proto=ESMTP, daemon=MTA, relay=outbound.broadmoor.com [209.177.136.194] 
(may be forged)
Oct 18 10:07:16 mx01 sendmail[10729]: j9IG7FxV010729: Milter: data, 
reject=451 4.2.1 mail j9IG7FxV010729 from 209.177.136.194 temporary 
greylist embargoed
Oct 18 10:07:16 mx01 sendmail[10729]: j9IG7FxV010729: 
to=<lindagay@sugarloaf.net>, delay=00:00:01, pri=39235, stat=mail 
j9IG7FxV010729 from 209.177.136.194 temporary greylist embargoed
Oct 18 10:17:18 mx01 sendmail[11493]: j9IGHGXe011493: 
from=<SFERGUSON@broadmoor.com>, size=9259, class=0, nrcpts=1, 
msgid=<1B255EB9A7B2E44697FDAB7CA49558F304E458D0@exchange.penrose.local>, 
proto=ESMTP, daemon=MTA, relay=outbound.broadmoor.com [209.177.136.194] 
(may be forged)
Oct 18 10:17:18 mx01 sendmail[11493]: j9IGHGXe011493: Milter: data, 
reject=451 4.2.1 mail j9IGHGXe011493 from 209.177.136.194 temporary 
greylist embargoed
Oct 18 10:17:18 mx01 sendmail[11493]: j9IGHGXe011493: 
to=<lindagay@sugarloaf.net>, delay=00:00:01, pri=39259, stat=mail 
j9IGHGXe011493 from 209.177.136.194 temporary greylist embargoed

Note that the last message was sent ~12 minutes after the first attempt. 
The greylister is setup to accept any properly resent message after 3 
minutes. For this particular message the greylister never accepts it 
even though everything (sender Email, recipient Email, sending server IP 
address and msgid). Now I know the greylister works for other messages. 
Why might it have failed for this message and how to I go about 
debugging it?

Thanks for your suggestions.

-- 
Paul (ganci@nurdog.com)