[{"data":1,"prerenderedAt":42},["ShallowReactive",2],{"$f35ofng14y4jca":3},{"title":4,"seoTitle":5,"description":6,"route":7,"kind":8,"toolKey":9,"intro":10,"indexable":11,"sections":12,"related":38},"MX 查询","MX 查询 | nslookup.online","查询域名 MX 记录、邮件服务器优先级与 Null MX，补充查看目标 A\u002FAAAA 地址，不将 DNS 结果误称为投递验证。","\u002Fzh\u002Fmx-lookup\u002F","tool","mx","查看邮件路由记录及其优先级。",true,[13,20,26,32],{"id":14,"title":15,"paragraphs":16,"code":19},"read-answer","理解域名的邮件路由",[17,18],"输入邮箱 @ 后的域名，而不是完整邮箱。MX 记录指定邮件交换服务器及数值优先级，本工具按数字从小到大排序。","相同优先级的服务器是同级目标，不能据响应顺序指定唯一主服务器。本工具不连接 25 端口、不检查邮箱，也不发送邮件。","example.com.  3600  IN  MX  10 mail.example.com.\n\n文档示例 — 非实时 DNS 响应",{"id":21,"title":22,"paragraphs":23},"null-mx","Null MX 是什么意思",[24,25],"优先级为 0、目标为单个点号的 MX 表示该域名明确不接收邮件。它不是名为“点”的服务器，因此不会为此目标查询地址。","没有 MX 与 Null MX 不同：SMTP 标准在部分情况下允许回退到地址记录。因此仅凭缺少 MX，无法断言所有投递必然失败。",{"id":27,"title":28,"paragraphs":29},"addresses","补充地址与检测边界",[30,31],"目标的 A\u002FAAAA 可补充显示邮件服务器地址，但不能验证可达性、TLS 配置或服务器是否接受收件人。","最多为八个不同目标补充地址。补充查询失败会单独展示，不会隐藏成功的 MX 记录。",{"id":33,"title":34,"paragraphs":35},"questions","有 MX 为什么仍收不到邮件",[36,37],"可继续检查 SPF 和 DMARC，但已发布策略不保证投递成功。发件信誉、认证对齐、过滤、邮箱规则及 SMTP 行为均不在本查询范围内。","排查差异时应匹配名称、类型和解析器，并参考实际 TTL；不要预设所有变更固定需要 24 或 48 小时。",[39,40,41],"\u002Fspf-checker\u002F","\u002Fdmarc-checker\u002F","\u002F",1792661399212]