Connect and reconnect
Open Configuration, Connected sources, then add a Gmail mailbox. Reconnect the same mailbox when Google permissions change or the token becomes invalid.
Default sender
The first usable mailbox becomes the default sender. A workspace owner can change the default without disconnecting other mailboxes.
Disconnect
Disconnecting removes the stored OAuth tokens for that mailbox and stops new capture or sends through it. Existing workspace records are not silently reassigned to a different mailbox.