You can BCC yourself on every single email that Collins sends out.
Go to Settings
> Emails & Texts
Put the email you want to receive every email to in the "BCC all emails to (email)" box
Check the emails sent to the customer for a particular booking.
In your Collins system, got to your Enquiries page
> You'll see your list of New and In Progress enquiries here, if you want to search for a Confirmed booking you can either use the Search Bar tool or your Filter tool (How to use your Filter Tool)
> Select the booking/enquiry
> When in the details screen for that booking/enquiry, click the "Messages" tab at the top of the bookings details.
> There will be a Message History of all emails you have composed and sent to the customer
Please note: No Messages can be edited or deleted in this section