When I attempt to send mms, either my only choice is email, or, if I try to circumvent that, it tells me " no mms service record found, message cannot be sent. I bought this storm unlocked off eBay. It was originally a Verizon phone I'm trying to use with tmobile. How do I work out this problem without buying a data plan?

You need a BlackBerry Data Plan in order to send MMS.