One of our main mailservers (treehouse.forest.net 216.168.37.80) was blacklisted by a major spam filtering organization (Spamcop.net) earlier today. The server was on the blacklist for about 3 hours. We are investigating the source and working with spamcop.net staff to resolve this issue and prevent a repeat. Further details will be posted when we know more.

Since many secondary services use spamcop.net as a blacklist source, we expect a 'ripple effect' for the next 24 hours or so. Please be patient.