When specifiying one or more MediaUrls when sending a message, content types for MediaUrl validation are fetched via the content-type header at the provided URLs. If the content-type header does not match the media, Twilio will reject the request.
The following types of content are fully supported by Twilio for Media. This content will be formatted for delivery on destination devices.
The following types of content are accepted by the Twilio API for Media. Requests will not be rejected, but content will not be modified for device compatibility.