checkeremail.com

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

IP & reverse DNS

IP address	Reverse DNS (PTR)	FCrDNS	DNSBL
52.101.73.123	mail-am6pr02cu00203.inbound.protection.outlook.com	Yes	Not listed
52.101.103.36	mail-miypr05cu00104.inbound.protection.outlook.com	Yes	Not listed
52.101.103.162	mail-miypr03cu00202.inbound.protection.outlook.com	Yes	Not listed
52.101.68.21	No	Unknown	Not listed
2a01:111:f403:ca21::10	mail-matpr05cu00100.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:ca09::a	mail-am7pr02cu00202.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:c967::c	mail-cpjpr05cu00204.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:ca09::20	mail-as8pr05cu00400.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 AM4PEPF00027A63.mail.protection.outlook.com Microsoft ESMTP MAIL Service ready at Sun, 6 Sep 2026 20:13:46 +0000 [08DF0AF463FE4645]`

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

Domains using this mail server

cpk.pl

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.