In part 1 we set up the very most basic dovecot install we could get away with. In this part we will try to redeem it a bit by improving the security of the the authentication mechanism and the storage of passwords on the server. In other words we will make it much harder to snoop on our communications with the imap server and decrease the overall likelihood of somebody learning our password, including anybody with access – legitimate or otherwise – to our server.
This post follows up on the fifth installment in my Let’s do Postfix series. We’re not really done setting up Postfix but a) it’s about time we had a better way of accessing incoming mail than ssh’ing into our server and using
cat to read and b) we are at a juncture where the two will soon start depending on (SASL) and interacting with (LMTP) each other
This tutorial presumes knowledge of Postfix and the setup we’re aiming for is one that complements the Postfix one that we’ve set up in previous installments. As with the Postfix series I want to arrive at a working setup from the very first post but knowing full well that it’s not an ideal or final setup. The advantage (over importing somebody else’s full featured setup) is that we’ll actually understand what we have on our hands (and it’s shortcomings). This makes it a lot easier to build and improve upon it and fix it should the need arises.
A note on safety: The setup we’ll end up with today is not going to be confidential in any way, shape, or form. It will expose both the contents of the account’s emails and whatever password you choose to the entire internet. Therefore you should obviously use either a test account or a brand new one that has nothing important on it yet. As for passwords you should pick one for testing that you have not used nor intend to use for any non-testing purposes. That said, un-confidential is not the same as unsafe. Any public facing service is a potential attack vector but this setup is – to the best of my knowledge – no more of one than a more properly confidential setup.
Back in 2015 I embarked on an ambitious plan to blog my entire way through setting up my own selfhosted email server. I got a fair bit in (5 posts) before the setting up got ahead of the blogging and I lost track of scribbled notes and halfwritten posts. Moving to a fresh Ubuntu 18.04 install I decided to move as many services as possible to containers, including my email setup and so, rather than just copy paste my old config files I dug into the basics of email setup again.