Thanks to @erosco for all his hard work, determination and troubleshooting to come up with a solution for all User's of the GT-I9305, and more than likely other Galaxy models (and possibly other devices) out there that use a separate APN for Internet and MMS. erosco has stated that he added
to his build.prop and he was able to get MMS working. @rodman01 has stated he will add this fix for user's in the future rom releases for his roms to have it "out of the box" ,also I can't thank @erosco enough for finding a proper solution, please hit his thanks button http://forum.xda-developers.com/gala...0/post69843704 for solving this for us. Also attached is a screenshot erosco took to show what the build.prop should look like.
The app used in the screen shot is BuidProp Editor by JRummy you can download it here from playstore --> BuildProp Editor .To make it easier to give support please use that app if you are experiencing issues.
Ok so Basically I have by default a APN for data and another for MMS like in the first screenshot, but the way my APN is set by default it turns 4g to ! (on Marshmallow data doesn't break but just keeps saying sending MMS) When I send a MMS . So what I did was copy the APN information in MMS APN to the MMS section which was blank in the data APN like in the screenshots. The 2 and 3 screenshot is my default MMS APN so I copied that to the MMS section of the data APN like you can see in 4 and 5 screenshot to merge it .leave it as is but just add the MMS stuff were it applies and add MMS to APN type for instance my APN type now looks like this default,supl,mms also don't forget to add MMSC address and do not delete MMS APN ( thanks to @Fritly for the info) or it won't work. If you are still unable to use MMS read and try this http://forum.xda-developers.com/show...postcount=4063 thanks to @noc.jfcbs and @Wood Man If their posts help please hit their thanks button.
Hope this helps if anyone has anymore questions just ask I'll be glad to help. Thanks to @Anghirrim for testing