How can we track emails sent between our users across our application?

Question and Answers
1

How can we track emails sent between our users across our application?

2

We would like to track emails being sent / received across our application, how do we create a unique reference in an email?

You can modify the headers of the message to include a unique identifier, i.e X-AppName-UniqueID = to add this to the headers you would need to send and read messages using RAW MIME.

You can build a relationship database that maps emails across accounts, ensure you use the Header Message-ID’s, not the Nylas messages ID’s as these can change if the account is removed / added again.