The contact tags can be used in subject lines, content within the email body, and even within URLs.
The following is a screenshot of WYSIWYG content editor with Contact Tags drop-down highlighted:

Here is the list of predefined contact tags:
- {{contact.id} – The tag is replaced by the contact ID. The contact ID represents the internal identifier that the Maropost platform assigns to each contact in the system.
- {{contact.email}} – The tag is replaced by the contact's email address.
- {{contact.first_name}} – The tag is replaced by the contact's first name.
- {{contact.last_name}} – The tag is replaced by the contact's last name.
- {{contact.phone}} – The tag is replaced by the contact's phone number.
- {{contact.fax}} – The tag is replaced by the contact's fax number.
📋 Note: Remember that you can set the default value for the ‘first name’ and ‘last name’ fields on the field index page. This will add these values for the contacts that have no first name or last name present. This is useful while using {{contact.first_name}} and {{contact.last_name}} tags in content or the subject line of campaigns since it will be replaced by the default value stored in these two fields.