Full auditable chat history is stored on the homeserver and cryptographically signed by homeserver. Retention time is optionally configured by chat room. Matrix meets HIPPA requirements. Timestamps are recorded for all events.
Multiple homeservers can participate in a room¹. This is called “federation” and each homeserver has a copy of the conversation.
“Matrix is really a decentralised conversation store rather than a messaging protocol. When you send a message in Matrix, it is replicated over all the servers whose users are participating in a given conversation - similarly to how commits are replicated between Git repositories. There is no single point of control or failure in a Matrix conversation which spans multiple servers: the act of communication with someone elsewhere in Matrix shares ownership of the conversation equally with them. Even if your server goes offline, the conversation can continue uninterrupted elsewhere until it returns.
This means that every server has total self-sovereignty over its users data - and anyone can choose or run their own server and participate in the wider Matrix network. This is how Matrix democratises control over communication.“²
I recommend that MAF run a homeserver for each field office. For instance, if headquarters is maf.chat, then Indonesia could be id.maf.chat, and Alaska could be ak.maf.chat. This keeps the mirrored rooms close to the MAF personnel using them.
¹ “rooms” are like “channels” in Teams™.
² see “How does it work?” at https://matrix.org