Sending messages to txt.att.net are not delivered

Question

I am trying to text my phone using phonenumber@txt.att.net using our corporate email server. The message is never delivered to the phone. It works if I sent the message using gmail or another email server.

It worked with our corporate email until we changed to another internet service provider. We believe the problem has to do with a block on our new ip address range. We however do not get a non-delivery report from txt.att.net.

Who do we contact to get this resolved? We send alot of email to text messages using automated systems. We can text other mobile phone providers, the only issue is with AT&T.

Dan

curiouscat · Answer

This article will help you.https://www.att.com/esupport/postmaster/

h1ckman · Answer

at&t has started blocking business from sending emails to phones via txt.att.net & mms.att.net.  they want you to buy their service.  their blocking is flaky though so some are blocked and some get thru.  or like you noticed changing isp was a change and now fits their blocking rule set.