Outlook SSL certificate status
Valid — 112 days until expiry(outlook.com)
This page shows the Outlook SSL certificate as served by outlook.com, read from a live TLS handshake by an independent CertPost probe and rechecked hourly: expiry, issuer, hostname coverage, the full chain, and the negotiated protocol.
Last checked 2026-09-20 07:46 UTC. CertPost is not affiliated with Outlook.
Certificate details
Hostnames this certificate covers
outlook.com, *.hotmail.com, *.internal.outlook.com, *.live.com, *.office.com, *.office365.com, *.outlook.com, *.outlook.office365.com, attachment.outlook.live.net, attachment.outlook.office.net, attachment.outlook.officeppe.net, attachments.office.net, attachments-sdf.office.net, ccs.login.microsoftonline.com, hotmail.com, mail.services.live.com, office365.com, outlook.office.com, substrate.office.com, substrate-sdf.office.com
Certificate chain as served
Common questions
Is the Outlook SSL certificate expired?
At the last check, the certificate outlook.com serves was within its validity period. It expires on 2027-01-10, 112 days from that check.
When does the Outlook SSL certificate expire?
The certificate outlook.com is currently serving expires on 2027-01-10 (112 days from the last check). Large services rotate certificates long before that date.
Who issued the Outlook SSL certificate?
The certificate was issued by DigiCert Global G2 TLS RSA SHA256 2020 CA1.
How is this checked?
A CertPost probe opens a real TLS connection to outlook.com on port 443 and reads the certificate the server presents, the same way a browser does. The result is cached and refreshed hourly.
Outlook rotates certificates without downtime. Your own domains are the ones that expire quietly — watch 3 free, no card.
Monitor your certificatesOr run a one-off check with the free SSL checker.