Can no longer deliver mms messages to mms.att.net
Hi, as of a few days ago my company is no longer able to deliver messages to mms.att.net subscribers. We've been using these email notifications for our customers for many years now and it's been working flawlessly. We're currently seeing error message:
Deferred: host mx3b.txt.att.net[18.104.22.168] said: 452 4.1.0 <[email scrubbed]> requested action aborted: try again later
Please advise as to what we can do to resolve this issue.
IT Director of DIY Media Group, LLC