Bulk email domain MX checker: which addresses are at a domain with no mail server?
In short: Paste email addresses and see, row by row, whether the domain after the @ has a mail server, only an address record, or nothing at all. Limit: Reads the domain, never the mailbox: a mail server says nothing about whether a person's address exists.
A bulk email domain MX checker reads the domain after the @ in each address and asks DNS whether it has a mail server. Paste up to 1,000 unique domains a run, or 5,000 after a free Google sign-in, and every address gets a row: has MX, address record only, null MX or no mail server. It checks the domain, not the mailbox. Download the CSV.
Price: this tool is free. Checking a whole email list is from $9/mo, and the first 100 checks are free with Google, no card. Check your list free nowSee pricing
Sample result
jane@acme.example is at a domain with a mail server; bo@gone.example is at one with none.
- Address
- bo@gone.example
- Domain
- gone.example
- MX records
- None
What this means for you
A missing mail server means every address there bounces. A working one says nothing about the mailbox.
- MX, then address record, then null MX
- One row per address
- Dead domains filtered in one click
- CSV out, nothing emailed
- MX
- Null MX
- DNS
By SimpleVerifier Team · Last updated
Also in: Português (Brasil) · Español · Deutsch · Français
Got a list with addresses at domains that may be dead?
- Paste it above to find the addresses at domains with no mail server, with a CSV of every row.
- Upload or paste it at /verify. Every address gets a live mailbox check, and the first 100 email checks are free with a Google sign-in, no card.
How do I check which email addresses have a domain with no mail server?
- Paste email addresses, one per line, or upload a CSV. Addresses are found anywhere in the text, so a whole export works.
- Press Check mail servers. Only the unique domains are sent, never the mailbox names, 100 a request. No mail is sent.
- Read each row: Has a mail server, No MX with an address record only, Accepts no mail (null MX), No mail server or DNS didn't answer.
- Filter to the addresses at dead domains, download the CSV, and hand the rest to the mailbox check.
Example
- You enter
- Four addresses:
jane@acme.example(a domain with MX records),sales@globex.example(an address record only),ana@initech.example(a null MX) andbo@gone.example(no records). - You get
- jane: Has a mail server, with the MX hosts. sales: No MX, address record only. ana: Accepts no mail. bo: No mail server. Download the CSV.
- Limits
- Up to 1,000 unique domains a run without an account and 5,000 when signed in with Google. 100 domains a request; DNS only, nothing is emailed.
What does a missing MX record mean for an address?
A domain's MX records say which servers take its mail. When there are none, RFC 5321 tells a sending server to fall back to the domain's address record. When there is neither, there is nowhere to deliver, and mail to every address at that domain bounces.
Lists collect these from old signups, mistyped forms and companies that closed or let a domain lapse. Finding them by domain is cheap, because a list of 5,000 addresses usually has far fewer unique domains.
What are null MX and address-record-only domains?
A null MX (RFC 7505) is a single MX record with a dot as its host. It is how a domain says it never takes mail, so every address there will bounce. A domain with no MX but an address record can still receive mail by the fallback rule, but a working mail setup almost always has MX, so those rows deserve a look.
To see who hosts the mail on the good domains, use the bulk email provider lookup.
What does a domain with a mail server still not tell me?
Nothing here connects to a mail server or asks about a person. A domain with a healthy MX can hold mailboxes that were closed years ago, and a catch-all domain accepts everything. That question needs the mailbox check, which asks the mail server about each address.
Use this as the cheap first pass: remove the addresses that cannot receive mail, then check the rest. See what a hard bounce is for why those matter.
Who uses this tool, and for what?
- Marketers
- Remove addresses at dead domains before an import into an email platform.
- Sales teams
- Spot purchased-list rows whose company domain no longer takes mail.
- Agencies
- Add a mail-server column to a client list audit and export it as CSV.
- Developers
- Triage a signup export for addresses that can never receive mail.
What can’t this tool tell you?
- Reads the domain, never the mailbox: a mail server says nothing about whether a person's address exists.
- Only the MX records and, when there are none, the address record are read.
- Up to 1,000 unique domains a run without an account, 5,000 signed in.
- A DNS timeout shows as DNS didn't answer; run the list again.
Common questions
- How do I find email addresses with no mail server?
- Paste the list into a bulk email domain MX checker like this one. It reads each address's domain, asks DNS for MX records and shows the ones with none.
- Is this bulk email domain MX checker free?
- Yes. It is a free tool: up to 1,000 unique domains a run with no account, and up to 5,000 a run when you sign in with Google, with no card.
- Does it tell me whether the mailbox exists?
- No. It checks the domain, not the mailbox. A domain with a mail server can still have a closed mailbox.
- Is a domain with no MX but an address record dead?
- Not strictly. Mail can still be delivered to its address record. It is flagged because few real mail setups look like that.
- Does it send an email to test the domain?
- No. It reads DNS only and never opens a connection to a mail server.
- What is a null MX?
- A single MX record whose host is a dot (RFC 7505). It means the domain accepts no mail at all.
Sources
A tidy list can still be full of dead addresses.
Extracting, deduplicating and syntax checks all work on the text of an address. None of them can tell whether the mailbox exists. Only the server that hosts it can answer that, through an SMTP check, and that is what the paid product does.
- Upload the cleaned file as it is: CSVs up to 100,000 rows
- A real SMTP mailbox check on every row, with catch-all detection
- Small list? Starter at $9/mo covers 2,500 emails a month, cancel anytime
Plans from $9 a month, cancel anytime, no contract. Sign in with Google and your first 100 email checks are free, no card. The free tools stay free either way.