We all hate spammers. Many spammers would use domains in Taiwan or China or Africa. People caught on to this, and started blocking all mail from domains from those countries. The spammers countered by using hosts without DNS records. Anti spammers countered by requiring a DNS record to relay mail through them.
All was good.
Now ATT doesn't have DNS records for their customers, so now our customers who use Verizon at home can no longer e-mail through us, because they look like spammers to sendmail.
So, because Verizon has it's thunb up it's ass, do we allow hosts without DNS records to relay through us (including spammers), or do we tell our Verizon using customers they are S.O.L.?