No but they are implementing a SSL connection for future installs, but supporting the non ssl for previous installs which makes absolutely no sense, but that's pretty much the story of this company form a tech perspective all the way through. Its possible they have just fubared that getting it all ironed out and you need to wait a few days, if the web client works in the mean time its a nice work around but should not o be a permanent thing.
You may be able to look up the SSL info at »customer.comcast.com
somehow if you want to try changing the client to use it but I imagine they borked up both sides if that is the case. Note this will require you specify a different email port and that you require ssl.
Curious do you have an arris dory though? It seems SSL and them are having some issues from other posts, if you are set up on the SSL e-mail connection that may be the same problem.