On Wed, May 26, 2010 at 11:17 AM, Mike Walter <mwalter@3z.net> wrote:
We have been struggling to locate someone at AT&T that handles the txt.att.net servers. We have clients in our data center that can no longer send emails to mobile phones via 10digit@txt.att.net. We have contacted AT&T and they say there is no problem on their end. We can ping the server, but simply cannot connect to port 25. We have checked all firewalls of each client. Some ranges of IPs work and others don't. Looking for someone with a clue who can assist.
this is not a guaranteed service, nor does it have an official SLA, and inbound mail/connections from louder speakers are often just dropped, either at the TCP layer, or at the application layer (even after what seems like a completed SMTP conversation.) If you depend upon SMS for things, smtp -> sms gateways at the provider aren't reliable enough.