Bill,
It appears that 155.229.2.2 (postal.atlanta.net) may be blackholed. We were getting used to relay spam until a couple weeks ago when we worked in some sendmail filters to block use as a relay...
-Dorn
I have no idea why you took this to NANOG but since you did, I'll tell you publically that what happened was that the problem was name service rather than mail relaying: ;; ANSWERS: softcell.com. 172800 NS NNTP.ATLANTA.NET. softcell.com. 172800 NS POSTAL.ATLANTA.NET. ;; ADDITIONAL RECORDS: NNTP.ATLANTA.NET. 172800 A 155.229.2.177 POSTAL.ATLANTA.NET. 172800 A 155.229.2.2 The domain contacts at Atlanta.NET did not answer their mail. If you can let me know that this pure-spam organization is no longer a customer and that you are not helping them to send me trash by selling them name service I will remove the blocks instantaneously. Sorry to bother NANOG with this. (Can we take it offline?)