PM Mailbox limits

I know, it's all "I want, I want, I want...."

Would it be at all possible to increase the size limit on mailboxes?  I'm in a constant state of trying to figure out which PM to delete so that I have more room.  And yes, I know I could copy and paste into some other document to save the information and then delete the original, but - I'll admit it - I'm lazy and would like to just keep PM's in my mailbox where I'll be able to remember where to look for them.

Is it too late to ask Santa for this small request?  

Your ever-admiring, wanna-be-beta-tester,

StartingToTri