It has come to my attention that XO has "done away" with some of concentric's email systems and have replaced them with new "XO SMTP servers" these new XO SMTP servers aren't allowing people who don't have their mail hosted at XO to relay mail through them even though they are XO DSL customers, you guys may want to rethink your policy on this. It is generally the responsibility of the ISP to provide the outgoing mail transport for your connected users.

-Drew