//go:build go1.17 // +build go1.17 package mail import ( "fmt" "os" ) // WriteToTempfile will create a temporary file and output the Msg to this file // The method will return the filename of the temporary file func (m *Msg) WriteToTempfile() (string, error) { f, err := os.CreateTemp("", "go-mail_*.eml") if err != nil { return "", fmt.Errorf("failed to create output file: %w", err) } defer func() { _ = f.Close() }() return f.Name(), m.WriteToFile(f.Name()) }