I have an email address with "spam" in the name (this is through gmail) and lately I've had all kinds of problems with emails to it disappearing - I've had to call several places and have them change my email because I can't log in and the reset emails don't ever show up... but changing to myfirst.mylast works fine.

I've run into this with both Sam's Club and Speedway Rewards.

Only thing I can think of is that some outbound mail service they're using is dropping them, or some relay in the middle is dropping them... I can see where the word "spam" would be a keyword you might use, but I've had this email address for 15 years now and it's only been a problem in the last few years.