I have had no problems with my Adelphia EMail account, the ONLY thing I have done is change the servers.
For Adelphia people, BOTH "should" work(for a year after migration) > user@adelphia.net using mail.adelphia.net or user@roadrunner.com using pop-server.roadrunner.com,smtp-server.roadrunner.com. -- He doesn't have issues, he has a subscription.
Haven't had any problems with mine either. Email to me comes either as @adelphia.net or @roadrunner.com ...depends on whomever is sending it to me. -- Lonnie