Share your experience!
Hello to whoever sees this and can/cannot help,
I purchased my phone from Vodafone and it was a only internet sim card installed, I recently unlocked my device to use other service providers which I'm currently with optus on the xa f3115, I can receive/send sms and phone calls but cannot do this with MMS.
I've tried every app to fix this and I've have no luck, I called Sony and went to both Vodafone and optus and they don't know I've asked a couple phone repair guys and both said it's a hardware problem.
Only thing I found through apps and secret codes was ( modem config : is Vodafone)
PLEASE HELP SOMEONE!!
If it was a hardware problem, it would have never worked. It looks like the internet and mms settings from optus were not saved (that's if you have downloaded them or allowed the config sms to install them). Try downloading the internet and mms settings again or ask optus to send them again to you. MMS will always use data even if you are connected to wifi.
Thank you for the help I appreciate it, I've factory reset the device, I've reset network settings, I've spoken to optus 3 times and in 1 day literally on and off for ages, I've gone into systems settings being my second last resort and here being my last before I throw it in the river.
APN SETTINGS are correct and saved internet works fine without a issue, chrome, Google etc, I'm just confused and honestly seeking help.
I've even put another sim in there and not working even one from the same provider that I purchased this phone from.
Ps. Please help I'm begging I can't handle going on fb or whatsapp to mms people (no privacy)
Do you have both APNs set up: optus mms and optus internet?
Hi. I had a similar problem. While the mms APN needs to set up for MMS it is also important that the internet APN needs to be also set up correctly. In my case I had a prepaid vodafone xperia xa unlocked with Yomojo as my service providor. I had the APN internet set as per the Yomojo settings and then had trouble sending and receiving MMS. I then contacted Yomojo and got the Yomojo MMS APN set up and still could not get mms. After much searching online and chat support with Yomojo with no success i went to a vodaphone store in h st Perth and the consultant looked at my APN internet settings and changed the APN type to have the word "default" in it. After that the MMS function worked.
Wow - that works!!!! Same for me unlocked vodaphone XA, exact same issue. putting the actual word "default" in the internet APN works. Yoyu are awesome for posting, Thanks 
Thank you guys for the advice above, please note this worked on my Sony Xperia X as well.