Been running my own email server since January 2000. Most of that time, it's been running postfix, courier etc. I also run spamassassin, have reverse DNS set up

Been running my own email server since January 2000. Most of that time, it's been running postfix, courier etc. I also run spamassassin, have reverse DNS set up etc. No issues but then I also have few users receiving e-mail - about 10, including myself.