Returns string expression containing name and value of the header.

A String value.  

object.ToString

The ToString Method syntax has these parts:

ToString method will return string expression that is combined of header Name, semicolon and header Value, just as it appears in email body. For example, if header Name is 'From' and header value is 'techsupport@weonlydo.com' then ToString would return line like this:

From: techsupport@weonlydo.com

Notice that between Name and Value is one semicolon and one space character.