The email address of the sender (required).
property From: String read get_From write set_From;
This property is used to create a From SMTP header. This header identifies the sender of the message. A valid email address is required. Examples of valid addresses are: "Friendly Name" <firstname.lastname@example.org> or email@example.com
If the resulting header is longer than MaxHeaderLength, then it is folded according to RFC 822 specifications.