Seven mail ports
Direct TLS on ports 993, 995 and 465 and STARTTLS on 143, 110, 587 and 25. A separate result for each service.
Mail SSL Checker
Check mail server SSL
Enter the server name from your email client settings.
No password needed. The test does not log in to the mailbox or send any message.
Connection report
Test results
Not every server supports all ports. A failed connection may come from the service or firewall configuration and does not by itself mean a bad certificate. The test checks the negotiated connection, not all supported TLS versions or certificate revocation (OCSP/CRL).
Validity and trust
We check the validity dates, server name match and certificate verification. You will see the issuer, SAN names and expiry date.
What does the server negotiate?
See the TLS version and cipher suite used for the connection. We flag outdated TLS and certificates that expire soon.
Good to know
Which server name should I enter?
Enter the incoming (IMAP/POP3) or outgoing (SMTP) server given by your provider, e.g. imap.gmail.com. If these names differ, run a separate test for each. Your domain name is not always the mail server name.
How does TLS differ from STARTTLS?
Direct TLS encrypts the connection from the start. STARTTLS begins in the plain mail protocol and switches to TLS before login. In POP3 the command is called STLS. Our test stops after checking the encryption.
What does a certificate warning mean?
The certificate may be invalid, issued for a different name or not verifiable with our server’s trusted CA store. The details help find the cause. We also show a warning if the certificate expires within 3 days.
Where does the test run from?
From HOSTEDBY.PL infrastructure, against one public IP address returned by DNS for each port test. The result reflects the moment of the check and this network location. We do not look at mailbox contents. Rate-limit counters expire after a minute; the tool does not store reports.