Secure Exim server
How can i configure my exim4 server to keep it protected?
Today we noticed some emails sended through in, but this server dont is used to send emails, just to read.
Is possible someone used telnet to send emails, i need use DigitalOcean Firewall to block something?
This is the log of an email sent:
2018-04-17 14:56:34 1f8UqH-00063i-4z <= firstname.lastname@example.org H=(CUSTOMER-ISP) [CUSTOMER-IP] P=esmtp S=4189 email@example.com