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
52.101.194.17	mail-ch5pr02cu00401.inbound.protection.outlook.com	Yes	Not listed
52.101.41.24	mail-sj0pr03cu01600.inbound.protection.outlook.com	Yes	Not listed
52.101.40.28	mail-cy1pr02cu00104.inbound.protection.outlook.com	Yes	Not listed
52.101.9.21	mail-bl2pr04cu00205.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:c922::	mail-bl0pr03cu00400.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:f807::	mail-co1pr02cu00200.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:c902::4	mail-sj0pr03cu01504.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:c946::6	mail-ch5pr02cu00406.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 CO1PEPF00012E7E.mail.protection.outlook.com Microsoft ESMTP MAIL Service ready at Wed, 30 Sep 2026 15:14:31 +0000 [08DF1C6408D9C3C0]`

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

Domains using this mail server

activafac.com.br

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.