Problems receiving email from United Airlines

I can not receive email from United Airlines! I tested this to isolate the problem in multiple ways- I requested the United flight itinerary be sent (via a web request) to my address at xxx@mac.com and xxx@me.com and to my @icloud address. None of them worked. Then I had the same itierary sent to a work email address on the same computer and same network and received it no problem. I checked all my junk mail filtering- nothing from United was apparently flagged either on the web-version of macmail or my laptop macmail. Then, I requested United send the iterinary to my husband's @mac.com account- also would not go through! Again, tried same request to my work address- same host (ATT), same hardware, same network, same 5 minutes, same request from United. -- got the itinerary no problem. I could FORWARD the work email containing the United itierary to my @mac address-- got it- same 5 minutes etc. So this has got to be a filtering problem from Apple that they have not told us about! I cannot believe no one else has noticed thisn (see a Yahoo problem that others have reported)! I cant figure out how to let Apple know there is a problem!