Mail in a Box

This is a work-in-progress to create a one-click deployment of a personal mail server.

After spinning up a fresh Ubuntu machine, just run sudo scripts/start.sh and you get:

• An SMTP server (postfix) for sending/receiving mail, with STARTTLS required for authentication, and greylisting to cut down on spam.
• An IMAP server (dovecot) for checking your mail, with SSL required.
• A webmail client (roundcube) so you can check your email from a web browser.
• Mailboxes and aliases are configured by a command-line tool.
• Spam filtering (spamassassin) with spam automatically going to your Spam folder, and moving mail in and out of the Spam folder triggers retraining on the message.
• DKIM signing on outgoing messages.
• DNS pre-configured for SPF and DKIM (just set your domain name nameservers to be the machine itself).

Other things I'd like to add in the future are personal cloud services (file storage, calendar, etc.), an OpenID provider, a place for putting a simple homepage, support for Ubuntu cloud-init, etc.

The goals of this project are:

• Make the deployment of a mail server ridiculously easy.
• Configuration must be automated, concise, auditable, and idempotent.
• Promote decentralization and encryption on the web.

This project was inspired in part by 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/), Sovereign by Alex Payne (https://github.com/al3x/sovereign) and conversations with @shevski and @konklone.

This setup is currently what's powering my own personal email.

Before You Begin

• 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

• 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:

  ssh -i yourkey.pem user@10.20.30.40

You should see a command prompt roughly similar to:

root@box:~# (<-- blinking cursor here)

All command-line instructions below assume you've logged into your machine with SSH already.

Configuring the Server

After logging into your server with SSH and becoming root, type the following in the console:

sudo apt-get install -y git
git clone https://github.com/tauberer/mailinabox
cd mailinabox

Now you've got the Mail in a Box source code stored on your server. The next command starts the automatic configuration of the server:

sudo scripts/start.sh

You will be asked to enter the hostname you chose and the public IP address of the server as assigned by your ISP.

After that you'll see a lot of output as system programs are installed and configured.

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 your DNS setup will be more complicated. The user's email address is also his/her IMAP/SMTP username. Then enter the user's password.

It is safe to run the start script again in case something went wrong. To add more mail users, run tools/mail.py.

Configuring DNS

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.occams.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" ".)

Checking Your Mail

You can access your email at https://hostname/mail, where hostname is again the hostname you chose at the start.

If you want to set up a desktop mail client like Thunderbird, 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. You're using a "self-signed certificate" for SSL connections, so you'll get security warnings when you try to read and send mail. It's safe to permanently ignore the warning the first time you see it (but not if you see the same warning later on).

Checking that it Worked

...