there are two easy options on how to find outgoing emails from a process. The first one is to look up the so called audit trail. It is generally shown directly beneath your actions in WebDesk (not in Workspaces). There are all manual and automatic actions shown and you can click on most of them to look up the content.
The second option would be to look up all Reminders in your database. For every Domain (eg. Incidents, Changes, Requests, etc.) there are separate tables. For the Requests the tables would be rm_reminder and rm_reminder_recipient. In the rm_reminder the column rm_request_guid will guide you to the related request on rm_request and pm_process. This will only work if you do not tidy up your outgoing messages using a scheduled action or manual deletion.