I have backed up the apk file from my phone using titanium backup. See if you can install it as you would a normal application
If you can't, download the files I uploaded at the link below and unzip them only once then place the four files that you extract into the backup folder that titanium users on your device after you do that you should be able to go into your list of applications and titanium should recognize that you have a backup of your MMS app and you should be able to restore it.
UVUADML MMS TITANIUM RESTORE.zip
I hope that helps, if not, feel free to contact me and let me know and I will try to help you out