Check mail server ssl

To check the SSL/TLS configuration of a mail server, you can use various tools and commands. Here are a few methods:

Method 1: Using OpenSSL

1. Open a terminal or command prompt.
2. Use the following command to check the SSL/TLS certificate of the mail server:

   openssl s_client -connect <mail_server>:<port>

   Replace <mail_server> with the hostname or IP address of the mail server, and <port> with the port number used for SSL/TLS connections (usually 465 or 587).

For example:

openssl s_client -connect mail.example.com:587

This command will display information about the SSL/TLS certificate, including the certificate chain, subject, and expiration date.

Method 2: Using Telnet

1. Open a terminal or command prompt.
2. Use the following command to establish a Telnet connection to the mail server:

   telnet <mail_server> <port>

   Replace <mail_server> with the hostname or IP address of the mail server, and <port> with the port number used for SSL/TLS connections (usually 465 or 587).

For example:

telnet mail.example.com 587

Once connected, you can type quit to exit the connection.

Method 3: Using a web-based tool

There are several online tools that can help you check the SSL/TLS configuration of a mail server, such as:

• SSL Labs: www.ssllabs.com
• Qualys SSL Server Test: www.qualys.com/sslserver/
• SSL/TLS Checker: www.sslshopper.com/ssl-checker.html

Enter the hostname or IP address of the mail server and the port number used for SSL/TLS connections (usually 465 or 587) to run the test.

What to check

When checking the SSL/TLS configuration of a mail server, you should verify the following:

• The certificate is valid and not expired.
• The certificate is issued to the correct domain name.
• The certificate chain is complete and trusted.
• The SSL/TLS protocol version is supported (e.g., TLS 1.2 or higher).
• The cipher suite is secure and supported (e.g., AES-256-CBC or higher).

By using one or more of these methods, you can ensure that your mail server's SSL/TLS configuration is secure and compliant with industry standards.