This draws heavily on the "NSA-proof your email in 2 hours" blog post by Drew Crawford (http://sealedabstract.com/code/nsa-proof-your-e-mail-in-2-hours/) and Sovereign by Alex Payne (https://github.com/al3x/sovereign). I've made some tweaks to their setups.
* Decide what **hostname** you'll use for your new Mail in a Box. You may want to buy a domain name from your favorite registrar now. For the most flexibility, assign a subdomain to your box. For instance, my domain name is `occams.info` (my email address is something`@occams.info`), so I've assigned `box.occams.info` as the hostname for my Mail in a Box.
* Get a server. I've been a long-time customer of Rimuhosting.com which provides cheap VPS machines at several locations around the world. You could also go with Linode.com or any other cloud or VPS (virtual server) provider. (If you want to test on Amazon EC2, I've got instructions for you in ec2/README.md.) In a cloud environment like EC2 where your server's IP address is dynamic, this is a good time to assign a static IP (like a EC2 Elastic IP).
* Choose Ubuntu 13.04 amd64 as your operating system (aka a Linux distribution). You won't need much memory or disk space. 768 MB of memory (RAM) and 4G of disk space should be plenty.
* Once the machine is running, set up Reverse DNS. Each ISP handles that differently. You'll have to figure out from your ISP how to do that. Set the reverse DNS to the hostname you chose above (in my case `box.occams.info`).
* Log in with SSH. Again, your ISP will probably give you some instructions on how to do that. If your personal computer has a command line, you'll be doing something like this:
At the end you'll be asked to create a mail user for the system. Enter your email address. It doesn't have to be @... the hostname you chose earlier, but if it's not then every email address on that domain will have to be handled by your hostname.
Enter the user's email address (which is also his IMAP/SMTP username) and then its password.
Your server is set up as a nameserver to provide DNS information for the hostname you chose as well as the domain name in your email address. Go to your domain name registrar and tell it that `ns1.yourhostname` is your nameserver (DNS server). If it requires two, use `ns1.yourhostname` and `ns2.yourhostname`.
For instance, in my case, I could tell my domain name registrar that `ns1.box.occams.info` and `ns2.box.occams.info` are the nameservers for `occams.info`.
(In a more complex setup, you may have a different nameserver for your domain. In this case, you'll delegate DNS to your box for the box's own subdomain. In your main DNS, add a record like "box.occams.info. 3600 IN NS ns1.box.occams.info." and a second one for `ns2` (the final period may be important). This sets who is the authoritative server for the hostname. You'll then also need "ns1.box.ocacams.info IN A 10.20.30.40" providing the IP address of the authoritative server (and repeat for `ns2`). Then add an MX record on your main domain pointing to the hostname you chose for your server here so that you delegate mail for the domain to your new server using a record like "occams.info. 3600 IN MX 1 box.occams.info." (again the period at the end may be important). You'll also want to put an SPF record on your main domain like "occams.info IN TXT "v=spf1 a mx -all" ".)
Configuring Your Mail Client
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Your IMAP and SMTP server is the hostname you chose at the top. For IMAP, you must choose SSL and port 993. For SMTP, you must choose STARTTLS and port 587. Your username is your complete email address. And your password you entered during server setup earlier.
So far you're using a "self-signed certificate" for SSL connections. That means you'll get warnings when you try to read and send mail about a security issue. It's safe to ignore those.
