Centrum email checker: does this centrum.cz or atlas.cz mailbox exist?
In short: Asks the mail servers behind Centrum.cz E-mail whether a centrum.cz or atlas.cz mailbox exists, without sending anything, after syntax, domain, disposable and role checks. Limit: A valid result shows the server accepted the mailbox today, not that anyone reads it.
To check if a centrum.cz or atlas.cz address exists, enter it here. The checker asks the mail server for that domain about the mailbox at RCPT TO, then disconnects before any message is sent. Both domains rejected a made-up address with 550 5.1.0 #5.1.0 Address rejected. on 8 November 2026, so a missing mailbox comes back invalid and an accepted one valid.
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
Tuned for centrum.cz, atlas.cz. Five checks a minute, no account needed. Nothing is sent to the address — we ask its mail server whether the mailbox exists, then disconnect.
Sample result
[email protected] doesn't exist: Centrum's server rejected it.
- [email protected]
- Reason
- Mailbox not found
- Mailbox check
- SMTP, nothing sent
What this means for you
Invalid means remove it; a real mailbox would come back valid.
- Asks Centrum's server at RCPT TO
- Catch-all test with a random address first
- Catches typo domains with no mail server
- Flags disposable and role addresses
- Centrum
- centrum.cz
- atlas.cz
By SimpleVerifier Team · Last updated
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How do I check a whole list of Centrum and Atlas addresses?
- Export the list as a CSV or copy the email column; Centrum and Atlas rows and every other domain can go in together.
- Upload or paste it at /verify. The first 100 email checks are free with a Google sign-in, no card.
- For every list after that, Pro includes unlimited email verification. Fair use: the first 100,000 checks a month at full speed, then slower, never cut off.
How do I check a Centrum or Atlas email address?
- Type or paste one address, such as
[email protected]or[email protected]. - Press Check. The tool checks the syntax and domain, asks the server about a random address that can't exist, then about yours, and disconnects before anything is sent.
- Read the verdict: valid means the server accepted the mailbox and rejected the made-up one, invalid means it rejected the address, risky means the check didn't get a clear answer.
- If it comes back risky, check again later: with Centrum that is usually a cut-short check, not a bad address.
Example
- You enter
- One address:
[email protected]. - You get
- Valid when the server receiving centrum.cz mail accepts the mailbox after rejecting a random address; invalid ("Mailbox not found") when it answers
550 5.1.0 #5.1.0 Address rejected.; risky only when the check gets no clear answer. - Limits
- Five checks a minute per IP address, one address at a time, no account needed.
How do I check if a centrum.cz or atlas.cz address exists without emailing it?
Ask the mail server instead of the mailbox. On 8 November 2026 centrum.cz published four MX hosts under eco-mx.cz (centrum-cz-10mx1.eco-mx.cz and three more), and atlas.cz four matching atlas-cz-…eco-mx.cz hosts. That day a made-up address on each domain got 550 5.1.0 #5.1.0 Address rejected. at RCPT TO through this checker.
5.1.0 is the general "bad address" code rather than the more common 5.1.1, but it came at RCPT TO for a recipient that can't exist, so a missing mailbox comes back invalid ("Mailbox not found") and an accepted one valid. This is one check on one day; we have no earlier observation for these domains.
Why do centrum.cz and atlas.cz addresses go dead?
Both are Centrum.cz E-mail, run by Economia, a.s.: its service terms name the servers mail.centrum.cz, atlas.centrum.cz and volny.centrum.cz. The terms let Economia cancel a mailbox the user doesn't log in to for longer than 6 months, or one left completely unused for 14 days after it was created.
Six months is short for a webmail service, so old Czech contacts on these domains go stale fast. Economia's terms page lists one version for accounts registered before 25 March 2021 and one for later ones; the 6-month rule above is in the later version. Re-check Czech lists before a campaign, for example with the bulk verifier, and use the Seznam email checker for seznam.cz addresses.
What can this checker confirm at Centrum?
Each row is something the check runs on a Centrum address, and the result you can get from it.
| Check | Can we confirm it? | Result when it fails |
|---|---|---|
| Syntax (the address is written correctly) | Yes | Invalid |
| Domain and mail server (MX) | Yes | Invalid, with a typo suggestion where one fits |
| Disposable or role address | Yes | Invalid (disposable) or risky (role) |
| The mailbox exists | Yes: Centrum answers at RCPT TO (550 5.1.0 Address rejected) | Invalid, "Mailbox not found" |
| A temporary reply or timeout | No answer to read | Risky, worth checking again later |
| Someone reads the inbox | No checker can | Use opens, replies or a small first send |
Our checking server offered a made-up address and disconnected without sending, through this checker on 8 November 2026; earlier checks are dated in the text.
Who uses this tool, and for what?
- Czech shops and newsletters
- Drop cancelled centrum.cz and atlas.cz mailboxes before a campaign.
- Support teams
- Catch a mistyped address, or a typo domain like centrum.cy, before you reply.
- Lead buyers
- Confirm a handful of Czech webmail contacts before paying for or importing a list.
What can’t this tool tell you?
- A valid result shows the server accepted the mailbox today, not that anyone reads it.
- A temporary reply or a refused connection comes back risky, not invalid.
- Economia doesn't publish how its servers answer mailbox checks; the handling here is from one check on 8 November 2026, which can change.
- One address at a time, five a minute.
Common questions
- How do I check if a centrum.cz email address is valid?
- Enter it here. The checker confirms the syntax and mail server, then asks the server about the mailbox without sending. It rejected a made-up centrum.cz address on 8 November 2026, so a missing mailbox comes back invalid.
- Are centrum.cz and atlas.cz the same service?
- Yes. Economia's Centrum.cz E-mail terms cover the mail.centrum.cz, atlas.centrum.cz and volny.centrum.cz servers, and on 8 November 2026 both domains used eco-mx.cz MX hosts.
- Does Centrum delete inactive mailboxes?
- Economia's terms for accounts registered from 25 March 2021 let it cancel a mailbox the user hasn't logged in to for longer than 6 months.
- What does 550 5.1.0 Address rejected mean from centrum.cz?
- The server refused that recipient. Coming at RCPT TO for an address on its own domain, treat it as a hard bounce and remove the address.
- Is this checker free?
- Yes, five checks a minute with no account. For a whole list, sign in with Google for 100 free email checks, no card, or use a monthly plan.
Sources
That was one address. Most people have a list.
The free checker does five addresses a minute, one at a time — fine for spot-checking, useless for a CSV of 40,000.
- Upload a CSV up to 100,000 rows
- Valid, risky and invalid exported as separate files
- Repeat checks free for 14 days, no new connections
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.