Originally Posted by MrCoffee

I've also had issues with US Airways mobile boarding passes, and found out that it's an SMTP issue with USAirways.

(The easiest way to test this is to have the boarding pass sent to a @gmail.com email address. If it gets there, then they're still having this issue.)

If you run your own email, you'll see in your CPanel logs that it's being dropped.

It was due to usairwaysmobile.com sending from IP address "153.69.214.202", which isn't in their MX records.

I tried letting them know, but never heard back from USAirways.

After white-listing that IP address, I was able to get mobile boarding passes, but they need to update their MX records.