When selecting the recipients for an email, you can select a 'Filtered List' that 'Sends to all contacts'. This will result in the email being sent to every person that has participated in any of your events and new first time registrants.
If a past participant wishes to no longer receive emails from you, you can manually upload a CSV that excludes that person. However, you would need to manually exclude this person for every subsequent CSV you upload.
Alternatively, you can change the email of the participant's profile in Active Works Endurance so that the email becomes undeliverable:
Select the Blue Magnifying Glass icon at the top right of Active Works page
Search for desired individual and click on them
Click Blue Arrow beside person's name
Change email to an unfinished email address (e.g. from "test@gmail.com" to "test@gmail.co")
