EmailCheck / Questions问题页 / Why are a third of the addresses on my B2B list on catch-all domains?
Why are a third of the addresses on my B2B list on catch-all domains?为什么我 B2B 名单里三分之一的地址都在 catch-all 域名上？
Because many companies configure their domain to accept mail for every possible address — it guarantees no legitimate message is ever turned away at the server. Public data puts 30–40% of a typical B2B list on catch-all domains. That slice of your list cannot be “verified clean”; the workable approach is to segment it and rank it by risk signals instead of treating it like the rest of the list.
因为很多公司把自己的域名配置成：任何地址都收信——这样就保证任何一封正经邮件都不会在服务器门口被拒。公开数据里，典型 B2B 名单有 30–40% 的地址在 catch-all 域名上。名单的这一片没法「验干净」；可行的办法是把它分出来、用风险信号排序，而不是和名单其余部分一视同仁。
Why companies set their domains up this way公司为什么这样配自己的域名
Catch-all is a rational default for a business. Employees join and leave, people guess at addresses (firstname@, firstinitial-lastname@), and a rejected message can mean a lost lead that nobody ever hears about. Accepting everything and filtering afterwards trades a spam problem the company can manage for a silence problem it cannot. Small and mid-size companies — the bulk of most B2B lists — choose this most often, which is why the share is so high.
对企业来说，catch-all 是理性默认。员工来来去去，外人会猜地址格式（firstname@、首字母-lastname@），一封被拒的邮件可能意味着一条谁都不知道的线索就丢了。全收、事后再过滤，等于用一个可管理的垃圾邮件问题，换掉一个管不了的沉默问题。中小公司——多数 B2B 名单的主体——最常这样选，所以占比才这么高。
What it means for your list这对你的名单意味着什么
- There is a hard ceiling on verification. On a catch-all domain, no domain-level (or SMTP-probing) check can confirm a mailbox. Any tool that reports a clean verdict for that third of your list is scoring, not verifying.
- Don't delete them. A third of a B2B list contains real customers at real companies. Deleting on “unverifiable” throws away pipeline.
- Don't blend them either. Mail catch-all addresses as their own segment, in smaller batches, with bounce monitoring, so a bad pocket cannot damage the sender reputation your verified segment relies on.
- Rank by the signals you have. MX health, domain age, typo and disposable flags all still work on catch-all domains — EmailCheck returns them per address, with
catchAllRiskmarking the segment, and the batch endpoint's summary lets you see the segment's size before you send.
- 验证有硬天花板。在 catch-all 域名上，域名级（乃至 SMTP 探测）检查都无法确认邮箱。任何对这三分之一名单报告「干净」裁决的工具，都是在打分，不是在验证。
- 不要删掉它们。B2B 名单的三分之一里是真公司里的真客户。因「不可验证」删掉，等于扔掉管线。
- 也不要混着发。把 catch-all 地址当作独立分区分开发、小批量、盯退信，让坏口袋伤不到你已验证分区依赖的发信声誉。
- 用你有的信号排序。MX 健康度、域名年龄、拼写与一次性标记在 catch-all 域名上照样有效——EmailCheck 逐条返回，并用
catchAllRisk标出这个分区；批量端点的 summary 让你在发送前就看到这个分区的大小。
Try it on a real address拿真实地址试一下
Live call to the production API — the same check described on this page.
实时调生产 API——就是本页说的这个检查。
Scope, stated plainly: EmailCheck checks domains, not mailboxes — no SMTP probing, no claim that a specific mailbox exists. Every API response carries scope: "domain-level" and a note saying exactly what was checked.
范围说死：EmailCheck 查的是域名，不是邮箱——不做 SMTP 探测，不声称某个具体邮箱存在。每个 API 响应都带 scope: "domain-level" 和一段说明，把查过的范围写清。