Here's the Message Rule Properties dialog box:



In the Name text box enter a unique name for the custom field following the on-screen instructions. Then, enter the text you'd like the custom field expand to in the text box labeled Value. Mark the Html source check box if you'd like to use HTML tags in the text. Please note though, that if a message in which the custom field is included is a plain text message, the custom field will be automatically converted to plain text. Same process works the other way around. If a not HTML custom field is included in an HTML message, it will be converted to HTML.