I've also tried the above ( ie. APN of epc.t-mobile.com and MMSC of http://mms.msg.eng-tmobile.com/mms/wapenc, everything else blank) as well as all variations on the recommended settings for T-Mobile USA in the MMS wiki article ie. I changed the port to 9102 and also tried an MMSC of http://208.67.216.231/servlets/mms but to no avail -- I still get "Unable to retrieve message." :/

jdb2