[{"data":1,"prerenderedAt":42},["ShallowReactive",2],{"$f2lyy4ucejz7np":3},{"title":4,"seoTitle":5,"description":6,"route":7,"kind":8,"toolKey":9,"intro":10,"indexable":11,"sections":12,"related":39},"SPF 检查","SPF 检查 | nslookup.online","检查 SPF TXT 记录、语法、地址 CIDR 与 include\u002Fredirect 依赖，展示查询证据及静态分析边界。","\u002Fzh\u002Fspf-checker\u002F","tool","spf","读取 SPF 语法与 DNS 依赖，不虚构发件授权结论。",true,[13,20,26,32],{"id":14,"title":15,"paragraphs":16,"code":19},"read-answer","从发件域名开始",[17,18],"输入要检查 SPF 的域名。工具在 TXT 中识别 v=spf1 候选，保留资源记录边界；多条候选是配置问题，不能当作一条记录拼接。","此版本仅做静态配置分析，不接收发件 IP、MAIL FROM 或 HELO，因此不能判定某个发件主机是否获授权。","example.com. 300 IN TXT \"v=spf1 include:mail.example -all\"\n\n文档示例 — 非实时 DNS 响应",{"id":21,"title":22,"paragraphs":23},"dependencies","跟随 include 与 redirect",[24,25],"沿字面域名追踪 include、redirect，识别明显循环并保留 DNS 证据。存在 all 机制时不应用 redirect。","总请求、依赖深度和操作时长受产品上限约束。达到上限会标记未完成，而不是宣称成功或已违反协议限制。",{"id":27,"title":28,"paragraphs":29},"limits","查询项不等于浏览器请求",[30,31],"RFC 7208 限制的是实际 SPF 评估路径中触发 DNS 的项，浏览器 HTTP 请求数与静态依赖图项数是不同指标。","静态图可能包含实际发件路径未走到的分支。总数超过十仅为风险提示，不断言所有邮件必然 PermError；空查询和地址匹配需要发件上下文。",{"id":33,"title":34,"paragraphs":35},"questions","理解 all 与未支持路径",[36,37,38],"-all 表示未匹配发件方的 fail 意图，~all 表示 softfail，不一定是错误；+all 允许所有发件方。它们均不能保证进收件箱。","检查 IP CIDR 及常见机制和修饰符。复杂宏标记未完成，不虚构发件参数；ptr 不受推荐，也不会模拟其发件 IP 评估。","不自动展平 SPF，也不提供可直接发布的生成配置。变更前保留原记录，并在实际发件服务中验证。",[40,41],"\u002F","\u002Fguides\u002Fnslookup-command\u002F",1792661399278]