Create self-signed SSL using OpenSSL
This is how you can create self-signed SSL…
Download OpenSsl installer first:
https://slproweb.com/products/Win32OpenSSL.html
Generate private key first:
[YOUR_OPENSSL_BIN_PATH]\openssl.exe genrsa -out [YOUR_OUTPUT_PATH]\YourDomain.com.key 2048
Generate CSR request (set all data but set at the end empty password and company name):
[YOUR_OPENSSL_BIN_PATH]\openssl.exe req -new -nodes -key [YOUR_OUTPUT_PATH]\YourDomain.com.key -out d:\Utils\Certificates\YourDomain.com.csr
Generate certificate that is valid 10 years, or 3652 days
[YOUR_OPENSSL_BIN_PATH]\openssl.exe x509 -req -days 3652 -in [YOUR_OUTPUT_PATH]\YourDomain.com.csr -signkey [YOUR_OUTPUT_PATH]\YourDomain.com.key -out [YOUR_OUTPUT_PATH]\YourDomain.com.cert
Use this certificate for your email for example – set port 995 for incoming email and port 465 for outgoing email – put them into firewall (Inbound and Outbound rules) in Advanced Firewall settings