1. Install mod_ssl and python

yum -y install mod_ssl python26-virtualenv

2. Change into /opt and clone letsencypt

cd /opt

git clone https://github.com/certbot/certbot letsencrypt

3. Run letsencrypt

/opt/letsencrypt/letsencrypt-auto --debug

Select relevant options when prompted.

4. Setup auto-renew

Auto-renew certificates every Sunday at 6pm:

crontab -e
# Renew Let's Encrypt certificates at 6pm every Sunday
0 18 * * 0 root (/opt/letsencrypt/certbot-auto renew && service httpd restart)

DSA keys have since been deprecated. Use the following command:

ssh -oHostKeyAlgorithms=+ssh-dss -oPubKeyAcceptedKeyTypes=+dsa user@x.x.x.x

more filename.extension | mailx user@domain.com

Mac:

1. Thunderbird > Preferences > Advanced > General > Config Editor
2. Search for mail.identity.default.suppress_signature_separator;
3. Right click and toggle to true

Windows

1. Tools > Options > Advanced > General > Config Editor
2. Search for mail.identity.default.suppress_signature_separator;
3. Double click on false to toggle to true

After setting the server time with the following command:

dpkg-reconfigure tzdata

The syslog service now needs restarted:

service syslog restart

Tail the mail.log to check the entries are stamped with the correct time:

tail -f /var/log/mail/log