[ale] Email to txt.att.net (AT&T Mobile - SMS) being delayed

[Lightner, Jeff]

And is your carrier AT&T?

Do your applications send as specific users themselves have you done some sort of aliasing or masquerading to make Sendmail do that?

To be clear I don't believe the issue is an intrinsic fault in the way we're sending email in general.   As noted it works fine to at least 2 other cell phone companies.  I believe the issue is the way AT&T treats the email we send vs the way other carriers do.  My 2 questions were aimed at possible ways to mitigate that based on the findings I provided since they clearly aren't blocking all mail to text messages originating here.

It is also possible it is a volume thing.   We send many emails so it is possible AT&T is getting the majority of those and is blocking them but if so this is a recent development.    My fear is I'd put in one of the two mitigations I can think of (my original 2 questions) see it resolve the issue temporarily only to recur after AT&T determine the new way of doing it should be blocked.



-----Original Message-----
From: ale-bounces at ale.org [mailto:ale-bounces at ale.org] On Behalf Of Alex Carver
Sent: Monday, June 29, 2015 4:32 PM
To: ale at ale.org
Subject: Re: [ale] Email to txt.att.net (AT&T Mobile - SMS) being delayed

I use the SMS gateway all the time for my alarm system at home (monitored by a Linux machine at home and sending through my personal mail server) and there are no delays.  I can trip an alarm and receive the text message within three seconds using the txt.att.net bridge.

The from address on those messages is whatever I set in the headers.
For example, I have one of my Axis cameras sending a message when it detects motion.  It sends by way of my personal server and the message comes out as coming from "cam at acarver.net".  There's a couple scripts running on another machine watching smoke detectors and those relay out through my mail server too.  My relay MTA is exim on the server.

The current setup has anything that needs to send an alarm send a message to a special alias on my mail server.  That gets sent to my regular user account where procmail picks up the message, duplicates it and ships it off to the SMS gateway.  The response is immediate and the text message arrives at my phone the moment it leaves my server.

One thing I used to have in place was a MIME decoder because the message would be a mess of MIME and text.  I'm not using that currently, though.