Install a certificate on sendmail

First, you will need your private key file (not encrypted), your certificate file (cert-0000000000-1234.cer file), and your certificate chain file (chain-0000000000-1234.txt file).

If you haven't ordered your certificate yet, and want to generate a private key and a CSR, you can read our OpenSSL documentation.

Install

Then, edit your .mc configuration file and add/edit the following lines:

  define(`confCACERT_PATH',`/etc/mail/ssl/certs')
  define(`confCACERT',`/etc/mail/ssl/chain-0000000000-1234.txt)')
  define(`confSERVER_CERT',`/etc/mail/ssl/cert-0000000000-1234.cer')
  define(`confSERVER_KEY',`/etc/mail/ssl/privatekey.pkey')

Field description:

• confCACERT_PATH: Directory containing the server's Certification Authorities
• confCACERT: intermediate certificate file
• confSERVER_CERT: certificate file
• confSERVER_KEY: private key file

You can then restart sendmail.

Additional links

• Generate a private key and a CSR with openssl
• OpenSSL Documentation
• TBS Legacy sendmail documentation (not updated anymore)

• Official sendmail with STARTTLS documentation
• Official sendmail project page
• Digicert Documentation
• Comodo Documentation
• Third party documentation on sendmail with STARTTLS