Share your experience!
Hey,
I have had my xperia arc for just under a week now. When I first got it it was fine and was sending MMS messages no problem. But today for some reason it stopped. Whenever I try to send something I just get the 'sending' icon hovering over the image, I did a test and this lasted for at least 10 minuets before I gave up. I haven't done anything to the settings, nor have I changed the wireless networks. My signal is fine and I can sent text messages no problem. I am with T-Mobile and I have checked the APN settings more than three times and it all matches. I have also checked memory space and I have more than enough. The image does not say it is protected and I have tryed sending downloaded images and my own pictures but nothing seems able to get through.
I'm really struggling to work out what is wrong as like I said, it was working fine yesterday and text messages are working fine today. I would appreciate any and all help. Thank you x
I'd have a chat with T-Mobile, if I were you, as it sounds more like an issue with the
network rather than the phone.
I assume you still have a data connection? You need an active data connection to
send MMS messages, although I used to be with TM UK, and their data network
was always a little....iffy 
I agree it might be the network, few things you can do
test your SIM card on another phone if it works with other phones then a factory reset could solve the issue
make sure you backup everythig beforehand
Make sure you backup everything
Backup & Restore app
Use this links to download the apk
http://forum.xda-developers.com/showthread.php?t=1193802
or
http://www.elita-clan.com/downloads/backup_and_restore_v010935.apkhttp://www.elita-clan.com/downloads/backup_and_restore_v010935.apkor
http://www.mediafire.com/?1n07llajeaoo03y
How to install it
You need to
go to settings -> applications -> check unknown sources
download IO File Manager
https://market.android.com/details?id=org.openintents.filemanager&feature=search_result
download the backup & restore app, transfer it to your SD card, use OI file manager to find it -> tap on it -> install it
Contacts
just to play it safe sync your contacts w/ google if you haven't already
SMS/MMS
if you don't want to use the backup & restore app then
Install "backup SMS" to back up your SMS and MMS to your Gmail
https://market.android.com/details?id=com.zegoggles.smssync&feature=search_result
or your SMS use
"backup & restore SMS"
https://market.android.com/details?id=com.riteshsahu.SMSBackupRestore&feature=search_result
or for your MMS use "Save MMS"
https://market.android.com/details?id=com.schwimmer.android.mmsextract&feature=search_result
Call Logs
And for call logs this is great
https://market.android.com/details?id=com.yang.android.ansta