I am having a strange issue with fmms recently

I can recieve all mms messages (from all providers), I can send mms to tmobile (US) users and they are recieved. Anytime I try and send an mms to ATT, Verison, etc (anything other than Tmobile); fmms SAYS it is sent, but the user never recieves it.

I am using wap.voicestream.com but have also tried epc.tmobile.com

Ideas?

I double checked my settings

Currently using
wap.voicestream.com (in the fmms settings... the apn for internet is left blank but I have tried both epc.tmobile.com and wap.voicestream.com) with no luck

http proxy: shows as 216.155.165.50, the config settings wiki says 216.155.165.050 but everytime fmms cuts out that 0

port is 8080