imessage and iTunes account

Hi, I've been looking for a discussion that would cover my specific problem, so sorry if one already exists!

I cannot update or download apps from the app store ever since I used my iTunes ID email address to send/receive messages for iMessage. I signed into iMessage using my @mac.com account, but I used my gmail (itunes ID) account to send/receive messages. I followed the directions from another discussion by signing out of my iMessage and signing back in, but this time I put in a totally separate send/receive email address, thinking that my iTunes ID (gmail) was the problem. Still doesn't work. Every time I try to update/download my apps, a message appears telling me "You have not verified you Apple ID". It tells me it sent a verification email with instructions to my gmail account, but I am not receiving anything. (I've done this numerous times). Then, I tried signing out again and signing back in with my gmail iTunes ID instead of @mac.com, and put as my send/receive address the same gmail address, but iTunes still gives me the same verification message. These two Apple IDs are starting to get a little confusing, and it is frustrating not to be able to deal with apps all of a sudden without cause.

I hope this made some sort of sense. Ever since iMessage, I have not been able to deal with iTunes and the Store due to "verification". I don't think iMessage's send/receive email should have anything to do with my other account.

Any thoughts?

BTW, other threads concerning iMessage also mentioned iCloud. I do not have an iCloud account or use it.