mail/internal/mail/message.go
func (m *Message) SetBody(contentType, body string, settings ...PartSetting) {
	m.SetBodyWriter(contentType, newCopier(body), settings...)
}
func (m *Message) SetBody(contentType, body string, settings ...PartSetting) {
	m.SetBodyWriter(contentType, newCopier(body), settings...)
}
func ( m * Message ) SetBody ( contentType , body string , settings ... PartSetting ) { m . SetBodyWriter ( contentType , newCopier ( body ) , settings ... ) }
// SetBody sets the body of the message. It replaces any content previously set
// by SetBody, SetBodyWriter, AddAlternative or AddAlternativeWriter.
SetBody sets the body of the message . It replaces any content previously set by SetBody SetBodyWriter AddAlternative or AddAlternativeWriter .