If you are receiving a lot of "male" targeted spam, your address was most likely harvested by a virsus/hack on your PC or someone's PC who has your address stored in outlook. Since you say only you and United have this address, I would most likely suspect your computer is/was compromised. Most people don't realize today that most hacks/backdoors/viruses are aimed at getting email addresses for spammers and compromising PCs to be used by spammers. I run several corporate mail servers and have my own domain/server. Since you have control over your address, I would just come up with a new one and remove the old one.

I haven't seen any spam to my dedicated United email address yet.