I got this email from Yahoo (I'm sure you're seeing similar): Dear blahblahblah, As part of our continuing effort to provide you with a wonderful Yahoo! Mail experience, we want to make sure the mail you send gets to the friends, family or other contacts you are trying to reach. In support of this commitment, we have removed Yahoo! email addresses from your address book that are no longer valid. All other information remains part of your address book. Plus, it’s simple to import contacts from Gmail or Facebook in two easy steps. Get started now. The following email addresses have been removed: blah blah blah (Blahs' inserted by me of course) I know it has been wished here before to have a list of all the deleted accounts - or at least the ones to remove from our accounts. Yahoo of course knows. I wonder how this will affect mail. We'll all have to watch errors and hard bounces I suppose. Perhaps they will have a new error code for this.
AOL's been doing this for some time. I want to say, last I read, it was 30 days of inactivity they disabled your account. Obviously if you log back in again, it goes back live, but in the meantime for email it causes a lot of bounce issues and errors. Ultimately it comes down to how you choose to deal with your data and those bounces moving forward as some could come back live later when someone logs back in. Since they have been doing this, I do see a lot more bounces and 550's because of it.
I have not noticed our bounces go up much recently, so had little impact so far. Matt Lovett - www.wowmedia.eu
There was another post on yahoo's mail blog about a header you can add when sending mail to an account that allows you to check the "age" of the account. It was also posted here on the forum.. http://www.mailerforum.com/forum/showthread.php?4045-Yahoo-Announces-Help-For-Senders