Comcast retires domains

I just got an interesting email from Sender Score saying that Comcast is retiring several domains.

Why should you care?!

Well, if any of the email addresses that are in your database end with this domain (i.e. the part after the '@'), then they'll keep bouncing your email messages back to you, which can look bad in terms of deliverability. Deliverability basically means how well your emails get through all the spam traps (both user dictated and ISP dictated - sometimes emails will never even make it into someone's junk mail box because their ISP kept it from being delivered at all). If you want to evaluate how well your email advertising is going, then you want to have the best deliverability statistics available, and something like a retired domain can really screw with that.