checkeremail.com

checkeremail.com is a mail server (MX) used by 1 checked domain. Based on public DNS, it looks healthy.

IP & reverse DNS

IP address	Reverse DNS (PTR)	FCrDNS	DNSBL
52.101.10.10	mail-bn8pr05cu00102.inbound.protection.outlook.com	Yes	Not listed
52.101.50.13	mail-mw2pr02cu00605.inbound.protection.outlook.com	Yes	Not listed
52.101.50.10	mail-mw2pr02cu00502.inbound.protection.outlook.com	Yes	Not listed
52.101.9.87	mail-bl2pr02cu00507.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:f905::3	mail-dm5pr02cu00203.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:c91d::	mail-mw2pr04cu00100.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:f90a::4	mail-bnypr04cu00104.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:f909::6	mail-bn3pr04cu00106.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.

Server software

Detected software	Microsoft Exchange / 365 (from SMTP banner)
SMTP banner	`220 CO1PEPF000075F4.mail.protection.outlook.com Microsoft ESMTP MAIL Service ready at Mon, 28 Sep 2026 00:53:09 +0000 [08DF1C6FBFE11492]`

Captured passively during an earlier check — we do not actively scan mail servers.

Domains using this mail server

duke.edu

What does this mean?

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.