What is a catch-all domain, and should you send cold email to one?
A catch-all domain is a mail server configured to accept email for every address at that domain. Send to jane@company.com or to qwerty123@company.com and the server replies with the same acceptance. A verification service cannot confirm a single mailbox, so it labels the whole domain catch-all and leaves the decision to you.
You can send cold email to catch-all addresses. The safe approach is a small first batch, a close look at the bounce rate and a rule for what you do with the rest.
Why do companies run a catch-all?
An administrator sets one up so that a typo, a former employee's address or an old alias still delivers to someone. It saves a missed enquiry. Plenty of ordinary companies run this way, and the setting says something about the server. It says nothing about the person you want to reach.
Why can't verification confirm these addresses?
Verification works by asking the receiving server whether a mailbox exists, without sending a message. A normal server says no to an address it does not have. A catch-all server says yes to everything. The verifier gets the same answer for a real mailbox and an invented one, so the best result it can return is "catch-all".
Some providers add a risk grade on top, based on other signals. Treat it as an estimate. It ranks addresses by likelihood and confirms none of them.
What is the risk of sending to a catch-all address?
The server may accept your message at the door and then discover inside that no mailbox matches. In that case you receive a bounce after the fact, or you receive nothing. Silence is the worse outcome: the message vanished, and your reply count carries no sign of it.
The share of catch-all addresses in a B2B list varies a lot by industry and company size, and a list of small businesses will usually have more than a list of large enterprises. Measure your own list instead of relying on an industry average.
Should you send to them?
It depends on your list and your bounce history. The table gives a starting point.
| Situation | What to do |
|---|---|
| Catch-all addresses are a small share of a list that is otherwise verified | Send, in a separate small batch first |
| The address was found on the company's own site or confirmed by a reply before | Send. The catch-all label matters less when the address has a source |
| The address is a guess built from a name pattern | Hold it until you find a source or a risk grade you trust |
| Your domain is new or recently had a bounce problem | Leave catch-all addresses out until the rate is stable |
How do you send to catch-all addresses safely?
- Verify the whole list first. Run verification on import and read the status column before anything is sent.
- Split the list. Put the catch-all addresses in their own campaign or segment so their bounces do not hide inside the main rate.
- Send a small first batch. A few dozen messages is enough to see whether bounces appear.
- Read the bounce rate before you continue. If hard bounces stay low, send the next batch. If they climb, stop and suppress what bounced.
- Decide once per domain. A catch-all is a fact about the domain. Thirty people at one company are one decision.
How does anymail handle catch-all domains?
anymail does not probe mail servers itself. Catch-all status comes from your verification provider, or from a status column in the CSV you import, and ZeroBounce and NeverBounce can verify addresses before the first email. Flagged domains appear in a Catch-all queue inside To check, one row per domain, and nothing is deleted for you.
Each campaign also has a Catch-all verification setting with four options: Only verify, Maximum, Balanced and None. Only verify sends to confirmed valid addresses and holds every catch-all one. Maximum sends only to catch-all addresses graded deliverable. Balanced also sends to risky ones. None sends to all of them and is the default. Held contacts show a stopped status with the reason. The deliverability page lists the checks that run before a campaign starts.
Frequently asked questions
Why do companies set up a catch-all?
Administrators use it so mail sent to a mistyped or retired address still reaches someone. Plenty of ordinary companies run this way, so a catch-all status says something about the server and nothing about the contact.
Can an email verifier check a catch-all address?
Not with certainty. The server answers yes to every address, so the verifier can only report that the domain is catch-all. Some services add a risk grade, which is an estimate and not a confirmation.
Do catch-all addresses hurt deliverability?
They can. If the server accepts a message and then rejects it internally, you see a bounce later, and a high share of those raises your bounce rate. Sending in small batches keeps the damage small.
How does anymail treat catch-all addresses?
anymail marks catch-all domains in a To check queue and never deletes a contact for you. Each campaign also has a Catch-all verification setting with four options, and the default sends to all of them.
See which companies are warming up.
Start free trial