We've recently learned that the following domains have been retired by RoadRunner: jam.rr.com, midsouth.rr.com, mn.rr.com, se.rr.com, sport.rr.com, swfla.rr.com, ucwphilly.rr.com and houston.rr.com

Users at these domains have been transitioned to Comcast. In the transition process, users were able to choose a new email address. Meaning, it's not possible to simply convert an email address in your list from the old domain to the new domain – the username part of their email address has likely changed.

If your lists contain users at these domains, you'll see mail to them start to bounce as of January 7th, 2008. The ExactTarget system is handling these bounces properly and you should notice addresses at these domains being turned to “undeliverable” status. We're marking these domains as “dead” in our system, and very soon you will find them automatically removed at import time, via our List Detective.

Additionally, the domain adelphia.net belongs to a defunct ISP. Assets of the defunct cable provider Adelphia were purchased by and split between Comcast and RoadRunner, way back in 2005. Some users transitioned to <something>.rr.com email addresses, and some transitioned to comcast.net email addresses. For a long time, adelphia.net addresses were forwarding on to the recipient's new email address, but it appears as though mail to this domain is starting to bounce. The system is handling these bounces properly. We'll wait a short while, to confirm our suspicion that this transition is permanent. If so, we'll also mark this domain as “dead” in the system.