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
52.101.91.156	mail-maspr04cu00104.inbound.protection.outlook.com	Yes	Not listed
52.101.68.8	mail-du0pr03cu00100.inbound.protection.outlook.com	Yes	Not listed
52.101.68.25	mail-db8pr02cu00101.inbound.protection.outlook.com	Yes	Not listed
52.101.103.140	mail-miypr02cu00204.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:ca21::e	mail-matpr04cu00306.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:ca09::22	mail-am7pr02cu00302.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:ca3c::a	mail-zrxpr07cu00102.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:ca09::28	mail-am6pr02cu00300.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 CPH1EPF00000519.mail.protection.outlook.com Microsoft ESMTP MAIL Service ready at Tue, 1 Sep 2026 06:45:18 +0000 [08DF07B60043439C]`

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

Domains using this mail server

fiveguys.es

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.