I (me and my wife) run a small Debian 10/Buster web server with a few websites for friends and need to set up outgoing email. I've got to the point where I can send emails from the command line (
echo "Message Body" | mail -s "Message Subject" TARGET_EMAIL_HERE).
We need a set up that meets the following requirements:
- only a few emails each week are will be sent:
- some emails from a Perl contact form on a website (which needs tighter anti-spam protection, was going to use the Google CAPTCHA)
- some emails with document attachments from a theatre booking system that only known and trusted users can log into
- need a 'reply to' field in outgoing emails so people can hit "reply" in their email client (appears easy when setting up scripts to use mail servers)
- we don't want to allow any incoming email to the server
What we have:
- user websites are set up in their user directories (which are 755), but we administer the sites and they cannot log in to the server
- me and my wife are sudo-ers (two system admins) and the only people who login via SSH/SFTP
- root login is disabled
- We've changed the SSH port
I'm aware this is the bare minimum of info, but I'd like some guidance on setting up and securing Postfix for this kind of usage.