As you can see in this article here, your Bokun account enables you to set up automated messages to be sent out at various times such as:
On booking confirmation
X days before travel
X days after travel
On booking cancellation
On booking change
But you can also access a history of all the automated messages that have been sent out.
How can I access my Automated Message History?
You can see the history of all your automated messages by Customers > Automated messages on the left-hand side menu.
For each automated message there is a "History" tab where you can see the messages that have been sent.
Your automated message history consists of your customer's email address, the date the message was sent and the sender's email address. There is also a search bar at the top of the screen where you can search if a message has been sent to a specific email address.
Note that upcoming messages are also listed in the history, e.g. for a tour departing on 31st of December 2020, there's already a "1 day before" auto-message there for the 30th of December 2020 under "Date Sent".