Hello NANOG,
We recently started getting some complaints from customers experiencing an error when trying to access their old Comcast.net email accounts with one of their email clients (outlook tbird etc.) via POP3 or IMAP. Web based use of their email via the Comcast portal is unaffected.
“ERR [AUTH] Temporarily blacklisted IP Address - try again later”
These customers are previous Residential HSI subscribers of Comcast who have since moved to other internet service providers, including ours, and are still allowed to use their old email accounts.
There is a web portal based method for attempting to get individual IP addresses removed from the “temporary black list”. But due to the number of reports we have had in a very short period of time we believe an entire range of IP’s (possibly a /17) has been blacklisted as of last Friday-ish
We’re having difficulty resolving this issue through Comcast customer support or the Comcast Security assurance team. So I’m looking to see if anyone from Comcast or someone who has had this issue before reach out off-list to assist with resolving this headache.