If I am on a volume restricted UMTS/EDGE connection:
while leaving the notebook on all day to be aware of new email with a check, let's say every 15 minutes, in absence of messages, system POP3, how much data consumes every check on the server for new mail?
This is to understand how much does it cost me in terms of my monthly 2GB budget if I choose this method.

Thanks for any tip, I did not find anything about it in Google. I suppose that POP in all cases should consume less then IMAP.

Ps. The connections are using all TLS or SSL where applicable.