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
52.101.11.17	mail-sn1pr0501cu00301.inbound.protection.outlook.com	Yes	Not listed
52.101.194.158	mail-ch3pr04cu00106.inbound.protection.outlook.com	Yes	Not listed
52.101.42.18	mail-co1pr03cu00302.inbound.protection.outlook.com	Yes	Not listed
52.101.50.10	mail-mw2pr02cu00502.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:c902::2	mail-sj0pr03cu01602.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:f901::	mail-bl3pr02cu00100.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:c803::	mail-bn1pr21cu00200.inbound.protection.outlook.com	Yes	Not listed
2a01:111:f403:f802::3	mail-sj0pr03cu01403.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 CY4PEPF0000E9D3.mail.protection.outlook.com Microsoft ESMTP MAIL Service ready at Fri, 24 Jul 2026 12:01:17 +0000 [08DEE92713C8AA97]`

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

Domains using this mail server

portoseguro.org.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.