Email domain report
Mount Sinai email format (mountsinai.org): verification & catch-all status
As of November 6, 2026, the most common mountsinai.org email format is [email protected], used by 94% of the at least 705 distinct mountsinai.org addresses mailfloss verified in the 90 days to November 6, 2026. In mailfloss's checks (latest November 6, 2026), mountsinai.org mostly rejected addresses that do not exist, so it is not a catch-all domain. 80% of mailfloss's mountsinai.org 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@- 94% of distinct addresses
- Catch-all
- No
- mostly rejects unknown mailboxes · checked November 6, 2026
- Mail routed through
smtp-agent05.mountsinai.org- Accepted on verification
- 80%
- of verifications, 90 days to November 6, 2026
Verification results
How mountsinai.org responds to email verification
How mountsinai.org answered when mailfloss verified its addresses in the 90 days to November 6, 2026, most recently on November 6, 2026.
Most common mountsinai.org email formats
| Format | What it means | Share | 95% range | Addresses |
|---|---|---|---|---|
[email protected] | First name, dot, last name | 94% | 91–97% | 665+ |
| — | Contains digits | 2% | 1–5% | 15+ |
| — | Other pattern | 2% | 1–5% | 15+ |
Shares are of the 705+ distinct mountsinai.org 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 mountsinai.org
| Response | What it means | Share of listed responses |
|---|---|---|
250 | Mailbox accepted the addressDeliverable | 83% |
550 5.1.1 | Mailbox does not existUndeliverable | 17% |
Only answers about the mailbox itself are listed.
Catch-all
No, mostly rejects unknown mailboxes
Last checked November 6, 2026
DNS, checked November 6, 2026
MX smtp-agent05.mountsinai.org
SPF published · DMARC published
Mailbox provider Microsoft 365
Free check
Verify an address at mountsinai.org
Type the part before the @. mailfloss asks the mountsinai.org 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 mountsinai.org
Mount Sinai 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 Mount Sinai use?
mountsinai.org. Its MX record points to smtp-agent05.mountsinai.org, with SPF published and DMARC published, checked November 6, 2026.
What is the most common mountsinai.org email format?
[email protected]: 94% (95% range 91–97%) of the 705+ distinct mountsinai.org addresses mailfloss verified in the 90 days to November 6, 2026. Next: "contains digits" at 2% and "other pattern" at 2%.
Is mountsinai.org a catch-all domain?
No. In mailfloss's checks (latest November 6, 2026), mountsinai.org mostly rejected addresses that do not exist, so it is not a catch-all domain. Because mountsinai.org 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 mountsinai.org addresses bounce?
Of mailfloss's mountsinai.org verifications in the 90 days to November 6, 2026, 80% were accepted, 16% were rejected and 4% got no clear answer.
How do I find or check an email address at mountsinai.org?
Build it from the person's name in the most common format, [email protected], then verify it before you send: mailfloss asks the mountsinai.org mail server about that exact address and reports what it answered. Because mountsinai.org is not a catch-all domain, a clear answer means what it says. Verify one now.
Does Mount Sinai 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.
Typo Fixer · company domains
A subscriber who typed mountsinia.org is still a customer of Mount Sinai.
Most verifiers mark mountsinia.org invalid and delete the subscriber. mailfloss's Typo Fixer suggests mountsinai.org instead, checks whether that mailbox exists, and queues the fix for you to approve. Nothing changes behind your back.
On your signup form
Example: a subscriber types first.last@mountsinia.org; Typo Fixer suggests first.last@mountsinai.org and queues it for your approval.
Other domains mailfloss reports on
All domains| Domain | Most common format | Accepted on verification | Catch-all |
|---|---|---|---|
| northwestern.eduNorthwestern University | [email protected]40–45% of addresses | 85–88% | catch-all: No |
| orlen.plORLEN | [email protected]87–95% of addresses | 82–86% | catch-all: No |
| roche.comRoche | [email protected]85–88% of addresses | 73–76% | catch-all: No |
| siemens.comSiemens | [email protected]85–99% of addresses | 50–54% | catch-all: No |
| tum.deTechnical University of Munich | [email protected]81–85% of addresses | 82–86% | catch-all: No |
| uk-essen.deUniversity Hospital Essen | [email protected]90–99% of addresses | 82–87% | catch-all: No |
One check is a start. Keep every address on your list deliverable.
mailfloss runs this verification on your whole list, inside your email platform, and keeps running it as addresses change. Product teams and AI agents get the same checks from the API.
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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