First, we need to start by explaining where these email addresses come from and who they are provided by. If your email address ends in att.net/bellsouth.net/pacbell.net, that means you received your email address as a free “perk” for paying AT&T for internet service. Yahoo.com addresses are the only ones that are genuinely free and provided by Yahoo. Now, a while back, AT&T sold the management of their email addresses to Yahoo. Yahoo currently owns/manages all att.net/sbcglobal.net/pacbell.net addresses.
Suppose you cancel your dial-up, DSL, or U-Verse internet service with AT&T, which provided you with the free email address. In that case, your email address will eventually be eliminated by AT&T without notice. It could be days after you discontinue your internet service; it could be months, it could be years. Once they terminate your account, it is permanently gone, as all of your emails will be as well. Suppose you lose your account password or get otherwise locked out (like if your password is hacked, which is VERY common on these addresses as they are the most hacked email accounts in the world!). In that case, the free tech support provided by Yahoo will very likely NOT allow you to regain access to your account. It would appear that Yahoo did a “sweep” of old versions this past weekend and eliminated MANY old accounts, as we have been inundated with users experiencing this issue today.
In addition, we are seeing a higher and higher incident of yahoo.com/att.net/bellsouth.net/pacbell.net addresses refusing to remain working when they are being checked in external mail programs. That means you check your email in a program like Microsoft Outlook, Mac Mail (the “postage stamp program”), EM Client, Thunderbird, etc., you are likely eventually going to face technical issues (such as error messages saying your password is wrong, unable to send but can receive, unable to receive but can send, etc.). If the issues are resolved, they are incredibly likely to recur. It would appear that Yahoo is intentionally sabotaging their customers by changing settings required by third-party mail programs to stay functional, to force users to visit their yahoo.com website to check their mail, where they will earn ad revenue from your visit.
This brings us to the conclusion that we at Computer Dave ask that you immediately plan to move to a new email address (like Gmail). Unfortunately, we will no longer be able to repair these accounts in their relationship to third-party mail programs. We hope you can see the severity of the situation (that you may eventually lose your email altogether without any further warning!), so we encourage you to be PROACTIVE rather than REACTIVE.