func (m *Message) Attach(filename string, settings ...FileSetting) {
	m.attachments = m.appendFile(m.attachments, fileFromFilename(filename), settings)
}
func (m *Message) Attach(filename string, settings ...FileSetting) {
	m.attachments = m.appendFile(m.attachments, fileFromFilename(filename), settings)
}
func ( m * Message ) Attach ( filename string , settings ... FileSetting ) { m . attachments = m . appendFile ( m . attachments , fileFromFilename ( filename ) , settings ) }
// Attach attaches the files to the email.
Attach attaches the files to the email .