Specifies the e-mail address of the author of a content item.
Returns a string or Boolean value depending on use.
Standard use: Returns the e-mail address of the content item's author as a string.
Used in a conditional statement:
Returns TRUE if the content item author has a defined e-mail address.
Returns FALSE if the content item author has no e-mail address.
Can be used to alert the content item author through e-mail when a revision is made.