Not applicable to most installations, but I use geographical filtering on all
ports other than 25. Fine if you are the only user of the email system. I don't
block countries where I will send and retrieve email. I augment this with a
small blocking list of IP space where I'm OK if they read my
At a bare minimum, do the same blocking for AWS. The jq program mentioned on
the page works great.
http://docs.aws.amazon.com/general/latest/gr/aws-ip-ranges.html
I block the cloud services as they hack me. There aren't many left that I
haven't seen. Sadly my VPS, Digital Ocean, has an email ha
