When a contact is unenrolled in a sequence because of an error, you can re-enroll the contact at the next step from the sequence summary page.
Please note: if you use the Re-enroll option, the contact will be enrolled in the exact same sequence they were in at the time of unenrollment. If you made any changes to the sequence, the contact would not receive any of the updated emails. Learn how to re-enroll contacts after making updates to the sequence.
Please note: contacts who have unsubscribed from emails cannot be re-enrolled.