I have had this problem for several years with AOL addresses, but the Yahoo bounces just started last week. I've been communicating with several people with yahoo addresses successfully until 1/11/24. As others have mentioned, the bounce notice arrives several days after email is sent. SocketError.
Your instructions want me to have my recipients contact THEIR mail admins. This clearly is not an individual problem, it's blanket across ALL yahoo addresses. For goodness sake FIX THIS!!
My current workaround is to forward incoming email from yahoo to a gmail account, where I can respond and my reply actually reaches the addressee--y'know, the way email is SUPPOSED to work.