T-Mobile ... Can't send/receive mms on wifi

Whenever I am on wifi, I cannot send or receive MMS. When I turn off wifi all the messages go thru.

Here are my TMO apn settings: (Southeast, USA)
Name: Tmobile GPRS
APN: fast.t-mobile.com
Proxy: not set
Port: not set
username: not set
password: not set
server:not set
MMSC: not set
MMS Proxy: not set
MMS port: not set
MCC: 310
MNC: 260
Authentication: not set
APN type: default,supl
APN Protocol: IPv6
APN Roaming: IPv4
Bearer: unspecified
MVNO type: none

:confused: