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
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