func (p MailBuilder) Subject(subject string) MailBuilder {
	p.subject = subject
	return p
}
func (p MailBuilder) Subject(subject string) MailBuilder {
	p.subject = subject
	return p
}
func ( p MailBuilder ) Subject ( subject string ) MailBuilder { p . subject = subject return p }
// Subject returns a copy of MailBuilder with the specified Subject header.
Subject returns a copy of MailBuilder with the specified Subject header .