AT&T Error 0x800CCC0F is caused by a server issue and often prevents users from sending or receiving emails. You can refer to the suggestions given below to fix the error0x800CCC0F and regain access to your AT&T account:
•Check the email ID of the recipient and ensure it is typed correctly.
•Review your internet connectionbefore you access AT&T.
•Log out of your AT&T account and then try and log in again.
•Change your firewall settings so that it does not interfere with AT&T
If you find that the issue persists, you can call the ATT email customer service number and ask for additional technical assistance to fix the problem.