Hey I have the same problem! Just yesterday I got an email to my comcast.net address from flightaware perfectly fine telling me one of my photos was picked as a staff favorite. However, every time Flight Alerts tries to send me an email about one of my tracked flights I get the same problem as you are having. I’ve checked my spam folder/settings… no sign of any emails.
This appears to a problem that only affects Comcast users. Comcast has been mistakenly flagging FlightAware emails as spam for months and sometimes bounces them as undeliverable, which we then receive and mark the email address invalid.
We have been attempting to contact Comcast for months to resolve this issue but they have not responded.
Well the system was working for 3 or 4 days. I have my alerts now sent to my iPhone and email. All weekend long and the past few days both were getting alerts. Today, only the iPhone got them and for the first time in a few days I logged on to Flight Aware and got the big banner on the top that states my email address has a problem. Yes. I’m on Comcast. Don’t know how this helps you but just reporting in the Comcast bug is again doing its work…
I get hundreds of pieces of mail to that address each day. Unless the system is sending mail with a known virus attached, I couldn’t tell you why it’s bouncing. I do not see anything in my logs suggesting flightaware attempted to send me mail.
As a test, I logged out and at the log in screen clicked “I forgot my password” and the system was able to send me a new password.
Only slightly annoying, but I would like to get my alerts going again …
One or more of your mail servers isn’t implementing SMTP correctly. Some do, but some don’t. That explains why some of your messages get through to me, and some don’t; but it doesn’t explain why you send mail differently from different parts of the site. Here’s an article that explains it pretty well:
Short answer: you have an SMTP sender that looks/acts like a spammer. Besides being out of conformance, it’s probably responsible for plenty of other problems. This is the first time I’ve seen a non-spammer using this technique (“slamming”) but even if it saves you some CPU cycles, it’s probably not a great idea.