Knowledgebase

Sendmail can be configured to encrypt email via the secure socket layer (SSL) when you want to send and receives emails.

1) Open sendmail configuration file (usually: /etc/mail/sendmail.mc) with write access: # vi /etc/mail/sendmail.mc

Now append/modify following directives:

• define(`confCACERT_PATH',`/etc/mail/ssl/certs') -- location to find certificates
• define(`confCACERT',`/etc/mail/ssl/ca-bundle.crt') -- Root Bundle file (Make sure you select your server software as Apache & mod_ssl)
• define(`confSERVER_CERT',`/etc/mail/ssl/sendmail.crt') -- Domain Certificate
• define(`confSERVER_KEY',`/etc/mail/ssl/sendmail.key')
  And make sure port is set to smtps (secure smtp i.e. port 465): DAEMON_OPTIONS(`Port=smtps, Name=TLSMTA, M=s')dnl
  
  
  
  2) Restart sendmail and secure pop3s/imaps (optional, use the following if using POP/IMAP)
  
  
  
  Type the following commands to restart sendmail and related services:
  • • # /etc/init.d/sendmail restart
    • # chkconfig pop3s on
    • # chkconfig imaps on
    • # /etc/init.d/xinetd restart