checkeremail.com is a mail server (MX) used by 1 checked domain. Based on public DNS, it looks healthy.
| IP address | Reverse DNS (PTR) | FCrDNS | DNSBL |
|---|---|---|---|
| 52.101.243.110 | mail-ku3p306cu00306.inbound.protection.outlook.com | Yes | Not listed |
| 52.101.243.150 | mail-ku0p306cu01106.inbound.protection.outlook.com | Yes | Not listed |
| 52.101.243.112 | mail-ku2p306cu00800.inbound.protection.outlook.com | Yes | Not listed |
| 52.101.243.108 | mail-ku0p306cu00904.inbound.protection.outlook.com | Yes | Not listed |
| 2a01:111:f403:cc6d::2 | mail-ku3p306cu00302.inbound.protection.outlook.com | Yes | Not listed |
| 2a01:111:f403:cc6d::4 | mail-ku2p306cu00804.inbound.protection.outlook.com | Yes | Not listed |
| 2a01:111:f403:cc6d::6 | mail-ku0p306cu01106.inbound.protection.outlook.com | Yes | Not listed |
| 2a01:111:f403:cc6d:: | mail-ku0p306cu00900.inbound.protection.outlook.com | Yes | Not listed |
FCrDNS (forward-confirmed reverse DNS) passes when the IP’s PTR name resolves back to the same IP. It is a key signal that a mail server is legitimately configured; servers without it are widely treated as suspicious.
| Detected software | Microsoft Exchange / 365 (from SMTP banner) |
|---|---|
| SMTP banner | 220 KU4PEPF00000017.mail.protection.outlook.com Microsoft ESMTP MAIL Service ready at Mon, 10 Aug 2026 12:24:04 +0000 [08DEF48B560F6016] |
Captured passively during an earlier check — we do not actively scan mail servers.
These are public DNS facts about the mail server checkeremail.com — the host that other servers connect to when delivering email for the domains above. We do not actively probe it over SMTP; the checks here are reverse DNS, forward-confirmed rDNS and public blocklists.
To look up a specific domain’s mail setup use the MX Lookup, or verify an address with the email checker. Learn more in email servers explained.
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