Hey aafa!
The settings you have entered within your device are correct. It seems, however, that you are missing a place where to enter the MMS proxy, 205.151.11.13. I would suggest contacting HTC with the settings and asking them where to input them. You can reach HTC at 1-866-449-8358.
@ Community: Can anyone using a similar phone with working MMS assist?
The settings you have entered within your device are correct. It seems, however, that you are missing a place where to enter the MMS proxy, 205.151.11.13. I would suggest contacting HTC with the settings and asking them where to input them. You can reach HTC at 1-866-449-8358.
@ Community: Can anyone using a similar phone with working MMS assist?
Take the plunge aafa - unless MMS has NEVER worked before - you need to reset your phone.:(
Here's my story - I have the ATIV S and MMS became an issue for me as well. Everything worked except for MMS. It took me quite a while until I figured out that the apn settings on our 'mobile network' is completely useless and this is confirmed by going to the 'diagnosis' app. You can download it by dialling ##634# from your phone app. Then type *#9908#, tap Edit Profile (Edit Proflie). These are the apn settings that the phone will abide too nothing else.
If MMS will work for you without resetting your phone, this will be the place to set it up.
First - Delete all the apn settings from everywhere (mobile network), apn app from Samsung if you downloaded that as well. If there are profiles on the apn app from 9908 then I would suggest to delete that as well to wipe the slate clean although I would probably take note of what you have from the 9908 apn app.
Second - Pretty straight forward. You need 2 profiles (Although I think I was able to make it work with one on my previous setup).
1. Fido LTE
APN Name: FIDO LTE
Profile Category: internet (always on)
APN: ltemobile.apn
IP type: IPv4
GSM/CDMA: GSM
Everything else is blank or left alone.
2. Fido MMS
APN Name: FIDO MMS
Profile Category: mms
MMSC: http://mms.fido.ca
APN: ltemobile.apn
IP type: IPv4
Proxy address: 205.151.11.13
Proxy port: 80
GSM/CDMA: GSM
That's it. The quickest way to verify if it will work is to check FIDO MMS once you save the profile. IF it recategorizes it to 'other' and deletes proxy information then your out of luck. You'll have to reset the phone. I'm not entirely sure of the exact details but in my search for a fix I read that the MMS profile is set separately which makes sense but cannot be accessed directly thus you are not able to change it properly once you set it. I might be totally off but one thing is for sure - the phone thinks that there is already some sort of MMS profile (which is obviously broken) and you can only have one, which is why no matter what type of attempt you make to get it to recognize a profile as an MMS one, it breaks it.
I know I mentioned that I was able to make it work - and it was working until I chatted in with Fido and they "resent" their apn settings - that completely *uc*ed up my settings. I figured I can just change it back if needed but as per what I stated above the phone refused every attempt to set a working MMS profile. The reason I agreed to the reset on my apn settings was tethering was not working after I changed some of my fido services, I thought it didn't migrate over and this was their solution since it was on. Which reminds me - you can add another profile for tethering called FIDO TETHERING - set it as "other" and the apn is ltedata.apn and just copy the same stuff from FIDO LTE. This is confirmed working as well. It looks like tethering is somehow tied to the MMSC as well since I could not tether as long as I didn't have a working MMS profile. I guess that makes sense since the MMS profile on smartphones was conceived for 'billing' purposes.
I am not sure what type of things you've tried but I've tried a lot and I mean a **bleep** load. From the apn settings on the mobile network set-up to the samsung apn apps, even the verizon apn app that they have. I played around with the root menu as well as I was trying to check if there was a way to just reset the network settings instead of the whole phone but no luck on that side either.
The reset wasn't as painful as I thought it would be - although I might discover something else that blew up as a result but I was mainly concerned with my text messages and apps list. That looks like it restored fine. Of course my photos and videos. My idea for the start screen was just to take a screen shot of each page so I can reset it up later on but overall with all my fido services working (text, mms, tethering, data) - I think it was worth it plus it looks like the 'data sense' app has also migrated over properly with the latest GDR or whatever the latest update is generally called for WP8. I added this last paragraph because I think I remember seeing your forum handle on one of the wp8 forums I ran into and you are refusing to reset your phone for the data sense app. 
If you are still having MMS issues then there's a lot more incentive for you bro. hehe
I offer this solution to others as well that has had a lot of headaches with their Ativ S. I know I have. 
I guess I can answer some other Ativ S question if I have encountered it already and solved. If there is any confusion - I will try my best to clarify it. 
PS: At the start I had 79% battery left and I was not hooked up to a charger. It took 30-45 minutes of my time to reset it.In this time - I've confirmed that text messages we're restored properly and half of the apps I have has downloaded. The APN settings are downloaded automatically as long as your fido sim is inside the phone and they are working settings. Confirmed text/mms/tethering are working fine. Now, I'm just waiting for the rest to move over. Use wi-fi to speed up the downloads but my point is as long as you've back up your stuff in full confidence, you can do this thing while you're on lunch or something.
As a profession I am a software developer and know a bit about OS generally speaking. I looked into Battery Sense, disable all the unnecessary apps that would run in background but mostly is the Email/Messaging/Phone/Music/Podcast apps that would drain the battery. Nothing new there, and I am using the phone like before.
Some things have changed for sure. When I look into the Settings->Cellular + SIM (or if you have your region set to Canada: Mobile + SIM), at the SIM Settings->Highest connection speed I don't have any more LTE (only 4G), thought the phone connects to LTE or at least it shows that. My wife's phone still has it with WP8.1 but no hard reset.
Definitely the hard reset put the phone into a different state then before. I expect that Rogers would fix all of this but the question is when? Will it be the end of the summer? GDR3 came on October last year as I remember and Rogers pushed it only in Feb this year.
And another usage for the Internet Sharing was actually at the gym. When I don't do weights I either do eliptical or treadmill and I use to tether to my Nexus 7 table and watch something on Netflix while exercising. Otherwise it's so boring, believe me
