Why didn't my email campaign get sent?

In Email Campaigns, users are able to view recipient engagement metrics for each campaign with one of those metrics being "Not Sent". Within this metric there is a list of contacts who did not receive the email and there is also a column titled "Reason" on the right side of the page. In that column you will see certain terms that are used to describe the reason as to why an email campaign wasn't sent to a contact. There are several reasons as to why an email campaign would not be delivered to a contact:

• Undeliverable -  Emails unable to be sent due to email provider errors. Example: emails that have bounced or have been marked as spam.
• Unsubscribed - The recipient has chosen to be unsubscribed from this email campaign.
• Merge Tag Error - Emails that were unable to be sent due to missing information from the marketing profile for merge tags to populate in the email template.  Example: Missing Agent last name or Agent phone number.
• Contact Tag Error - Emails that were unable to be sent due to missing information in the contact card for merge tags to populate in email template. Example: Missing contact email, birthday or last name.
• Blocked - Emails that were unable to be sent due to an invalid email or restricted domains.