Issue
When using Twilio Conversations for Group MMS, users may encounter two unexpected behaviors regarding how messages are delivered and logged for SMS participants:
- Dropped Text: When sending an outbound message that contains both a media file and a text body, the text is stripped, and only the media is delivered to the recipients.
-
SMS Logging for Group MMS: When sending a text-only Group MMS, the outbound message logs display an
SM(SMS) Message SID rather than anMM(MMS) SID. This often leads to the assumption that the group thread was fractured into individual 1:1 SMS messages.
Product
Twilio Conversations Classic
Resolution
Both of these behaviors are expected functionality within Twilio Conversations, but they require specific handling and testing approaches:
Media and Text Stripping (Product Limitation) For SMS (and WhatsApp) participants in Twilio Conversations, if a single message contains both media and text, the system will only deliver the media file. The text body is intentionally dropped.
- Workaround: To ensure SMS participants receive both the context and the file, the media and the text must be sent as two separate messages.
Text-only Group MMS Logging as SMS (SM SID) The appearance of an SM SID for text-only Group MMS is a logging artifact, not a delivery defect.
- When a text-only Group MMS is sent, it is routed internally through the standard Messaging path, generating an
SMSID in the Twilio outbound logs. - Before it is handed off to the carrier, the message is correctly converted back into a Group MMS.
- If you review the inbound logs at the actual destination handset, the message arrives properly with an
MMSID and stays intact within the native group thread on the recipient's phone. - Recommendation: Testing Group MMS behavior exclusively between Twilio numbers can be misleading due to these internal routing logs. Always test Group MMS delivery using real mobile handsets to verify the actual end-user experience.