confirmed there's a mail cap... ive reached it quite a number of times. thats really something the game should inform you about in some way. like when the mail doesnt send say "mailbox full" or something.
im stuck at 13 :( I hope they fix this soon as its pretty game breaking. Saying their game is live and having these type of issues doesn't bode well for future gaming. I wish i read the forums more... i actually saw this as a bug when reporting another but didnt know there were precautions to prevent it...