[{"data":1,"prerenderedAt":42},["ShallowReactive",2],{"$f3m43thxnkjr0o":3},{"title":4,"seoTitle":5,"description":6,"route":7,"kind":8,"toolKey":9,"intro":10,"indexable":11,"sections":12,"related":38},"MX 查詢","MX 查詢 | nslookup.online","查詢網域 MX 記錄、郵件伺服器優先順序及 Null MX，補充檢視目標 A\u002FAAAA，不將 DNS 回應誤稱為投遞驗證。","\u002Fzh-tw\u002Fmx-lookup\u002F","tool","mx","查看郵件路由記錄與優先順序。",true,[13,20,26,32],{"id":14,"title":15,"paragraphs":16,"code":19},"read-answer","理解郵件路由",[17,18],"輸入電子郵件 @ 後的網域，而非完整電子郵件。MX 指定郵件交換伺服器與數字優先順序，工具按數字由小至大排序。","同數值的目標為同級，不能依回應順序指定唯一主要伺服器。不連線 25 埠、不測試信箱，也不寄信。","example.com.  3600  IN  MX  10 mail.example.com.\n\n文件範例 — 非即時 DNS 回應",{"id":21,"title":22,"paragraphs":23},"null-mx","Null MX 的含義",[24,25],"優先順序 0、目標為單一點號，表示明確不收郵件，不是名為「點」的伺服器，不會對它查位址。","沒有 MX 與 Null MX 不同，SMTP 在部分情況允許回退至位址記錄，不能僅憑缺少 MX 斷言所有投遞失敗。",{"id":27,"title":28,"paragraphs":29},"addresses","補充位址與檢測範圍",[30,31],"A\u002FAAAA 可補充顯示目標位址，但不驗證可達性、TLS 或是否接受收件人。","最多補查八個不同目標。補充查詢失敗會單獨顯示，不隱藏成功的 MX。",{"id":33,"title":34,"paragraphs":35},"questions","有 MX 為何仍收不到信",[36,37],"可繼續查 SPF 與 DMARC，但策略存在不保證投遞。寄件信譽、對齊、過濾、信箱規則與 SMTP 行為不在範圍內。","比較前匹配名稱、類型與解析器，參考實際 TTL，而非假設固定 24 或 48 小時。",[39,40,41],"\u002Fspf-checker\u002F","\u002Fdmarc-checker\u002F","\u002F",1792661399364]