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.