Email domain report
ČEZ email format (cez.cz): verification & catch-all status
As of November 6, 2026, the most common cez.cz email format is [email protected], used by 71–100% of the at least 10 distinct cez.cz addresses mailfloss verified in the 90 days to November 6, 2026. In mailfloss's checks (latest October 26, 2026), cez.cz mostly rejected addresses that do not exist, so it is not a catch-all domain. 41–44% of mailfloss's cez.cz verifications in the 90 days to November 6, 2026 were accepted.
One address at a time, right on this page · counts rounded
- Most common format
first.last@- 71–100% of distinct addresses
- Catch-all
- No
- mostly rejects unknown mailboxes · checked October 26, 2026
- Mail routed through
smtp22.cez.cz- Accepted on verification
- 41–44%
- of verifications, 90 days to November 6, 2026
Verification results
How cez.cz responds to email verification
How cez.cz answered when mailfloss verified its addresses in the 90 days to November 6, 2026, most recently on October 26, 2026.
Most common cez.cz email formats
| Format | What it means | Share | 95% range | Addresses |
|---|---|---|---|---|
[email protected] | First name, dot, last name | 71–100% | 40–100% | 10+ |
Shares are of the 10+ distinct cez.cz addresses mailfloss verified in the 90 days to November 6, 2026. A range shows where a share can sit given the addresses behind it. Uncommon formats are combined, and the words in each format are placeholders, never real names.
SMTP responses from cez.cz
| Response | What it means | Share of listed responses |
|---|---|---|
550 5.1.0 | Mailbox does not existUndeliverable | 54–57% |
250 | Mailbox accepted the addressDeliverable | 43–46% |
Only answers about the mailbox itself are listed.
Catch-all
No, mostly rejects unknown mailboxes
Last checked October 26, 2026
DNS, checked October 26, 2026
MX smtp22.cez.cz
SPF published · DMARC published
Mailbox provider Microsoft 365
Free check
Verify an address at cez.cz
Type the part before the @. mailfloss asks the cez.cz mail server about that address and tells you in seconds what it answered: the same verification behind the results on this page.
Any other domain works too: type a full address. The result appears under the box; nothing you type is stored on this page.
Questions about cez.cz
ČEZ email questions, answered from this data
Every answer comes from the numbers on this page, 90 days to November 6, 2026.
What email domain does ČEZ use?
cez.cz. Its MX record points to smtp22.cez.cz, with SPF published and DMARC published, checked October 26, 2026.
What is the most common cez.cz email format?
[email protected]: 71–100% (95% range 40–100%) of the 10+ distinct cez.cz addresses mailfloss verified in the 90 days to November 6, 2026.
Is cez.cz a catch-all domain?
No. In mailfloss's checks (latest October 26, 2026), cez.cz mostly rejected addresses that do not exist, so it is not a catch-all domain. Because cez.cz mostly rejects mailboxes that do not exist, a permanent (5xx) "mailbox does not exist" or "account disabled" answer from it is reliable, and those addresses can come off your list; a 4xx answer is temporary, so retry it. An accepted answer is strong but not certain evidence that the mailbox exists. A full inbox or a busy mailbox is temporary, so recheck those later.
Do cez.cz addresses bounce?
Of mailfloss's cez.cz verifications in the 90 days to November 6, 2026, 51–54% were rejected, 41–44% were accepted and 5% got no clear answer.
How do I find or check an email address at cez.cz?
Build it from the person's name in the most common format, [email protected], then verify it before you send: mailfloss asks the cez.cz mail server about that exact address and reports what it answered. Because cez.cz is not a catch-all domain, a clear answer means what it says. Verify one now.
Does ČEZ use Google Workspace or Microsoft 365?
Microsoft 365, the mailbox provider on mailfloss's record. Its published MX record is not one mailfloss recognises, so whether a security gateway sits in front of it is not known.
Other domains mailfloss reports on
All domains| Domain | Most common format | Accepted on verification | Catch-all |
|---|---|---|---|
| charite.deCharité | [email protected]88–93% of addresses | 79–82% | catch-all: No |
| fedex.comFedEx | [email protected]69–77% of addresses | 57–61% | catch-all: No |
| lmco.comLockheed Martin | [email protected]55–68% of addresses | 61–69% | catch-all: No |
| mayo.eduMayo Clinic | [email protected]97% of addresses | 96% | catch-all: No |
| morganstanley.comMorgan Stanley | [email protected]81–89% of addresses | 55–59% | catch-all: No |
| mountsinai.orgMount Sinai | [email protected]94% of addresses | 80% | catch-all: No |
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Every number here comes from verifications mailfloss ran for its customers in the 90 days to November 6, 2026. Pages show rounded aggregates only: no email addresses, names or single results. Read how mailfloss measures email formats and catch-all status.
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