Email coming in with prodigy address instead of my att.net address

Me too. And it seems to bypass all filters.

We've changed all of our att.net passwords, run all our antivirus, tried more than one browser and pc and operating system (eg android) and it appears as if it's happening at the yahoo server level.  This needs a response from ATT or Yahoo.   Some come in with various prodigy email addresses instead of ours and some come in with the correct id and occasionally those that came in with correct id are then changing to the prodigy email address when we look at them later.  An example:  ***

[Edited for privacy-This is a public forum. Please do not post personal or unique information such as but not limited to full names, employee ID numbers, email addresses, phone numbers, account numbers, etc.]

I hope so too - don't know how to get their attention unless there's more activity on your original post.

Surely this is some form of hack.  I'm worried about sending email and infecting those to whom I send email

Yes - some of it never changes, some of it comes in (or goes out) with the prodigy id and some remains correct to my email address(es)

Same ... just some of the email