func validateEmail(address string, resolver core.DNSResolver) (err error) { _, err = mail.ParseAddress(address) if err != nil { err = core.MalformedRequestError(fmt.Sprintf("%s is not a valid e-mail address", address)) return } splitEmail := strings.SplitN(address, "@", -1) domain := strings.ToLower(splitEmail[len(splitEmail)-1]) var mx []string mx, _, err = resolver.LookupMX(domain) if err != nil || len(mx) == 0 { err = core.MalformedRequestError(fmt.Sprintf("No MX record for domain %s", domain)) return } return }