MMS Sending Limits in General

When sending MMS messages, it is important to keep file sizes small to ensure successful delivery. Most mobile carriers accept a total MMS payload, meaning all text and attached media combined, of around 300 KB to 1 MB. To stay safely within these limits and avoid failed or delayed messages, we recommend keeping any image, video, or audio attachment under 500 KB. Larger files may be automatically resized by the carrier, rejected outright, or delivered as a lower quality version. If a message needs to include a larger file, consider sending a secure link instead of an attachment.

MMS Teams Limitations:

• The maximum size for attachments is 3MB. Note that individual carriers may have additional limitations; see the General paragraph above. 
• It is recommended that only one attachment be sent at a time to avoid exceeding the carrier's size limit.
• Microsoft Teams Connector will support whatever file types your carrier supports. 
• To confirm supported file types, refer to your carrier's documentation.
• The carrier may change file names in transit. Do not be alarmed if the file name appears as a hash when it reaches the recipient.
• MMS attachments will be retained on the Microsoft Teams Connector server for one month.
• Twilio sometimes sends attachments as hyperlinks to an SMS message.