bbiandov wrote:wingrider01's post is irrelevant; nothing to do with html. AT&T is arbitrarily blocking SMTP; same problem here; upon testing I was impressed by their filtering; no matter what was the server that directly interfaced with AT&T's (google SMTP or O365) even if one of the flagged IPs or FQDN hosts is mentioned in the SMTP chain -- they will block it.
Changing that IP or FQND with temporary fake values fixes the problem. But that's not a fix, come on. What, if any, is AT&T's process to dispute? We don't have hookups on the inside of AT&T and front-end support peons are useless.
Any help will be appreciated. And NO and IPs are not black listed. AT&T just decided to block them???
nice necormancer, the thread is close to 2 years old, if you take the time to review the actual RFC that is the basis for the desing of the protocal you will see the answer