There are three ways to enroll a recipient into a campaign: Enrollment Triggers, Email Lists or Manual Enrollment
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It is very rare for an enrollment trigger to be used in conjunction with an email list. If you need the combination of the two, be very careful.
Re-enrollment
By default, a recipient (i.e. an email address) may be present only once in a campaign. It helps to think of it like this: a person can only be in one place at a time.
If unchecked: any requests to enroll an email address will be denied if an email address is already in the campaign, even if that email has a status of Finished.
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This is desirable for enrollment triggers like Abandoned Cart where you may wish to present a coupon to a recipient each time they abandon a cart.
Enrollment StoreFronts Filter
Check one or more screen branding themes to filter for those themes.
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When finished, click the Enroll button to complete the enrollment.