It is a short text that has the following form: $(xxxx) that you can include in bodies and header fields of messages sent or forwarded by MailXpert. The data fields will be expanded to the text they represent before sending the messages. Here's a list of built-in data fields you can use in every message (note that names are not case sensitive):

• $(List-Name) - name of the email service as entered on the Email Service Properties dialog box;
• $(List-Usage) - usage instructions for the email service (Email Service Properties dialog box);
• $(From) - full sender's address;
• $(To) - full recipient address;
• $(Reply-To) - contents of the Reply-To: field;
• $(Subject) - message subject;
• $(CC) - contents of the CC: field;
• $(From-Name) - pretty part of the sender's address;
• $(From-First-Name) - sender's first name or, if there was no pretty name, the email address;
• $(From-Middle-Name) - sender's middle name;
• $(From-Last-Name) - sender's last name;
• $(From-Email) - sender's email address without the pretty part;
• $(To-Name) - pretty part of the recipient's address;
• $(To-First-Name) - recipient's first name extracted from the pretty part of the email or email address if there is no pretty part;
• $(To-Middle-Name) - recipient's middle name;
• $(To-Last-Name) - recipient's last name;
• $(To-Email) - recipient's email address.

• $(Original-Header) - entire header of the original message;
• $(Original-To) - contents of the To: field of the original message;
• $(Original-From) - contents of the From: field of the original message;
• $(Original-Subject) - subject of the original message;
• $(Original-Date) - date the original message had been sent;
• $(Original-From-Name) - name of the sender of the original message;
• $(Original-From-First-Name) - first name of the sender of the original message;
• $(Original-From-Middle-Name) - middle name of the sender of the original message;
• $(Original-From-Last-Name) - last name of the sender of the original message;
• $(Original-From-Email) - email address of the sender of the original message.

• $(List-Display-Name) - display name of the email service;
• $(List-Email) - service's email address;
• $(Command-Email) - email address used to handle command messages;
• $(Post-Email) - email address used to broadcast messages by updates/news board kind of service;
• $(Authorized-Email) - email address of the person authorized to broadcast messages.

If you are using the Professional Edition you can define a number of custom fields per each subscriber record. You can then reference the fields by their names, e.g. $(City).