Finally got round to test fMMS ver. 0.3.1 (as a follow up to my previous test of ver. 0.2.8). Here's what I've got: Sorted out APNs on device, basically I have deleted "T-Mobile MMS" profile and added proxy address to main "T-Mobile Internet" profile, leaving "Use proxy" tickbox unchecked. That way same APN profile serves for general internet browsing as well as sending/receiving MMS.