package smtpd import ( "fmt" "strings" ) func parseAddress(src string) (string, error) { if src[0] != '<' || src[len(src)-1] != '>' { return "", fmt.Errorf("Ill-formatted e-mail address: %s", src) } if strings.Count(src, "@") > 1 { return "", fmt.Errorf("Ill-formatted e-mail address: %s", src) } return src[1 : len(src)-1], nil }