However, we haven't specifically implemented DNS-based black hole list checking.

We're refusing to communicate with other e-mail servers that don't do things exactly right further, if you've implemented the Sieve filter rules I laid out in part 2, we're also discarding mail without properly formed message IDs. The Postfix configuration we set up in parts 1-3 is pretty aggressive. We're going to answer all of these questions in this final installment. Even better, you can easily add aliases, so creating and using it at a skeevy website that requires e-mail registration and then deleting the alias takes only a few seconds.īut are there any extra steps we can take to increase security? What about one-time passwords or two-factor authentication? What about bolting on a webmail front end so we can access our e-mail from a browser? What about push notifications or calendaring? What about letting users set and change their own e-mail passwords? What else can we bolt onto our server, and what other configuration paths might we take to do things differently? After all, you can plug your mail account name and password into your mail app or your smartphone and send and receive e-mail. We've got all the right pieces in place to ensure that the mail we send gets delivered we've got OpenDKIM operational, and we've got DNS properly configured (including reverse lookups!). You all have persevered through quite a bit to get to this point: we have a functional and secure e-mail server that does a good job at ignoring or dumping off spam before it hits your inbox. Further Reading Taking e-mail back, part 3: Fortifying your box against spammers

Postfix blackhole all mail