When ABP is enabled it will block incoming and outgoing MMS messages. It also interferes in some way with how my phone communicates with my provider. I have had sim card errors such as no sim or invalid sim detected messages and forced restart, after restart sim works fine for awhile and then happens again. Disabling ABP resolves all issues.
I have an unlocked galaxy note 4 SM-910T (t-mobile variant) using an at&t prepaid sim card. My phone is rooted and I have installed the FireKatN4ANK4V9 ROM.
I have not tried changing my MMS port but I will, I'll post again to update how that turns out.