go邮箱信息获取服务

package main

import (
    "bufio"
    "fmt"
    "log"
    "net"
    "os"
    "strings"
)

func main() {
    scanner := bufio.NewScanner(os.Stdin)
    fmt.Printf("domain,hasMX,hasSPF,spfRecord,hasDMARC,dmarcRecord\n")
    for scanner.Scan() {
        checkDomain(scanner.Text())
    }
    if err := scanner.Err(); err != nil {
        log.Fatal("Error: could not read from input: %v\n", err)
    }
}

func checkDomain(domain string) {
    // DKIM、DMARC 和 SPF 是维护电子邮件安全的三种主要机制。
    // 相关协议可让您防止未经授权的服务器作为您的域发送，并为收件人提供一种验证电子邮件确实来自您的方法。
    var hasMX, hasSPF, hasDMARC bool
    var spfRecord, dmarcRecord string
    mxRecords, err := net.LookupMX(domain)
    if err != nil {
        log.Printf("error: %v\n", err)
    }
    if len(mxRecords) > 0 {
        hasMX = true
    }
    txtRecords, err := net.LookupTXT(domain)
    if err != nil {
        log.Printf("error: %v\n", err)
    }
    for _, record := range txtRecords {
        if strings.HasPrefix(record, "v=spf1") {
            hasSPF = true
            spfRecord = record
            break
        }
    }
    dmarctxt := "_dmarc." + domain
    dmarcRecords, err := net.LookupTXT(dmarctxt)
    if err != nil {
        log.Printf("error: %v\n", err)
    }
    for _, record := range dmarcRecords {
        if strings.HasPrefix(record, "v=DMARC1") {
            hasDMARC = true
            dmarcRecord = record
            break
        }
    }
    fmt.Printf("domain: %v\n hasMX: %v\n hasSPF: %v\n spfRecord: %v\n hasDMARC: %v\n dmarcRecord: %v\n",
        domain, hasMX, hasSPF, spfRecord, hasDMARC, dmarcRecord)
}