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
52.101.42.162	mail-ea3pr05cu00102.inbound.protection.outlook.com	Yes	Not listed
52.101.194.4	mail-ch4pr04cu00104.inbound.protection.outlook.com	Yes	Not listed
52.101.41.183	mail-byapr04cu00307.inbound.protection.outlook.com	Yes	Not listed
52.101.42.16	mail-co1pr05cu00300.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:c903::3	mail-mw2pr02cu00503.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:f90a::4	mail-bnypr04cu00104.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:f905::4	mail-dm2pr04cu00404.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:c922::	mail-bl0pr03cu00400.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 CY4PEPF0000E9D4.mail.protection.outlook.com Microsoft ESMTP MAIL Service ready at Wed, 12 Aug 2026 01:50:05 +0000 [08DEF62302C38A99]`

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

Domains using this mail server

hallmark.com

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.