Approved File Types
Only images and videos are permitted to be sent via MMS. All videos are converted to .mp4 and all images are converted to .jpg when they're uploaded to be sent.
Q: Why does a picture or video show up as a link in the recipient's inbox instead of rendered in the SMS thread?
A: Many devices (including all newer Apple devices) will prevent "rich previews" of multiemdia unless the sender is saved in the recipients address book as a contact.
File Size Restrictions
Images are restricted to 25MB, and videos are restricted to 50MB.
Q: Why can I send larger videos from my iPhone?
A: iPhones use iMessage, which doesn't have the file size limitations of traditional SMS.