Twilio offers full support (including resizing/transcoding when needed) for several media types when sending MMS messages, and also accepts many additional media types. For details, please see Twilio's Accepted Content Types for Media.
Potential Support Response Time Delays Due to Surge in Toll-Free Queries: We’re experiencing a surge in inquiries due to the November 8, 2023 Toll-Free Restricted Traffic Shutdown Deadline. We’re committed to helping you; please bear with us as there might be some delays. For more details, see Toll-Free Message Verification for US/Canada.