Because of increasing fight against unsolicited (SPAM) emails internet service providers (ISP) started to block 25 port for email sending. Because of this and also due to your information security you can start sending mails through encrypted connection (SSL). In this tutorial we will tell you how to enable encrypted connection for email sending (465 port) and receiving (993 and 995 port) in "DirectAdmin" control panel with a self-signed certificate.
If you want to use your own certificate you should skip first step and place your certificate key and private key in "exim.cert" and "exim.key" files.
The tutorial was prepared with our "DirectAdmin 1.5 with CentOS 6" template and is meant to work on our self-managed virtual private servers.
0. Preliminary requirements:
"DirectAdmin 1.5 with CentOS 6" template installed on server;
1. Generating self-signed certificate:
openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout /etc/exim.key -out /etc/exim.cert
2. Restarting "Exim" and "Dovecot" services:
/sbin/service dovecot restart
/sbin/service exim restart
That's it. From now on you will be able to use encrypted connection to check your email by 993 (SMTP), 995 (POP3) port or to send email by 465 (STMP) port.