Email domain report
King's College London email format (kcl.ac.uk): verification & catch-all status
As of November 6, 2026, the most common kcl.ac.uk email format is [email protected], used by 79–84% of the at least 185 distinct kcl.ac.uk addresses mailfloss verified in the 90 days to November 6, 2026. kcl.ac.uk routes incoming mail through Microsoft 365. In mailfloss's checks (latest November 5, 2026), kcl.ac.uk mostly rejected addresses that do not exist, so it is not a catch-all domain. 76–80% of mailfloss's kcl.ac.uk 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@- 79–84% of distinct addresses
- Catch-all
- No
- mostly rejects unknown mailboxes · checked November 5, 2026
- Accepted on verification
- 76–80%
- of verifications, 90 days to November 6, 2026
Verification results
How kcl.ac.uk responds to email verification
How kcl.ac.uk answered when mailfloss verified its addresses in the 90 days to November 6, 2026, most recently on November 5, 2026.
Where kcl.ac.uk stands among Microsoft 365 domains
Accepted on verificationshare of verifications accepted
76–80% kcl.ac.uk76–81% median of 49 Microsoft 365 domains
Leading listed formatshare of distinct addresses in the most common listed format
79–84% kcl.ac.uk85–95% median of 49 Microsoft 365 domains
Rejected on verificationshare of verifications rejected
10% kcl.ac.uk12% median of 39 Microsoft 365 domains
Most common kcl.ac.uk email formats
| Format | What it means | Share | 95% range | Addresses |
|---|---|---|---|---|
[email protected] | First name, dot, last name | 79–84% | 72–88% | 150+ |
| — | Other pattern | 7–11% | 4–16% | 15+ |
[email protected] | First name, middle initial, last name (dot-separated) | 2–5% | 1–9% | 5+ |
| — | Contains digits | 2–5% | 1–9% | 5+ |
Shares are of the 185+ distinct kcl.ac.uk 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 kcl.ac.uk
| Response | What it means | Share of listed responses |
|---|---|---|
250 | Mailbox accepted the addressDeliverable | 87–91% |
550 5.4.1 | Mailbox does not existUndeliverable | 11% |
Only answers about the mailbox itself are listed.
Catch-all
No, mostly rejects unknown mailboxes
Last checked November 5, 2026
DNS, checked November 5, 2026
MX kcl-ac-uk.mail.protection.outlook.com
SPF published · DMARC published
Free check
Verify an address at kcl.ac.uk
Type the part before the @. mailfloss asks the kcl.ac.uk 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 kcl.ac.uk
King's College London 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 King's College London use?
kcl.ac.uk. Its mail is routed through Microsoft 365 (kcl-ac-uk.mail.protection.outlook.com), with SPF published and DMARC published, checked November 5, 2026.
What is the most common kcl.ac.uk email format?
[email protected]: 79–84% (95% range 72–88%) of the 185+ distinct kcl.ac.uk addresses mailfloss verified in the 90 days to November 6, 2026. Next: "other pattern" at 7–11% and [email protected] at 2–5%.
Is kcl.ac.uk a catch-all domain?
No. In mailfloss's checks (latest November 5, 2026), kcl.ac.uk mostly rejected addresses that do not exist, so it is not a catch-all domain. Because kcl.ac.uk 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 kcl.ac.uk addresses bounce?
Of mailfloss's kcl.ac.uk verifications in the 90 days to November 6, 2026, 76–80% were accepted, 12% got no clear answer and 10% were rejected.
How do I find or check an email address at kcl.ac.uk?
Build it from the person's name in the most common format, [email protected], then verify it before you send: mailfloss asks the kcl.ac.uk mail server about that exact address and reports what it answered. Because kcl.ac.uk is not a catch-all domain, a clear answer means what it says. Verify one now.
Does King's College London use Google Workspace or Microsoft 365?
Microsoft 365, the mailbox provider on mailfloss's record. Its published MX record points there too, going by its public mail records as of November 5, 2026, with no security gateway in front of it.
Other company domains on Microsoft 365
All 49 Microsoft 365 domains| Domain | Most common format | Accepted on verification | Catch-all |
|---|---|---|---|
| longandfoster.comLong & Foster | [email protected]94–100% of addresses | 59–63% | catch-all: No |
| lsuhs.eduLSU Health Shreveport | [email protected]84–93% of addresses | 98% | catch-all: No |
| mcgill.caMcGill University | [email protected]85–99% of addresses | 86–94% | catch-all: No |
| med.unc.eduUNC School of Medicine | [email protected]55–63% of addresses | 76–79% | catch-all: No |
| merck.comMerck | [email protected]59–62% of addresses | 70% | catch-all: No |
| nuveen.comNuveen | [email protected]99% of addresses | 95% | 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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