When receiving MMS messages through Twilio, some phones/service providers may split multiple attachments up into multiple, separate text messages even though the originator of the text message attached them into the same text message.
When receiving the messages, is there some way (hopefully a key of some kind) that my app can use to determine that multiple messages coming in should be grouped together and consider part of the same text message?
Twilio supports inbound concatenated messages up to 1,600 characters. Inbound messages over 160 characters will also be received on your Twilio phone number as one single message.
While this is dependent upon carrier like you said, you can always check a messages instance resource, where messages are easily identified by their Sid.
And as Phil mentioned, if you are experiencing unexpected behavior send examples of those messages to Twilio Support for further examination.
