Mail-in-a-Box email

I used Mail-in-a-Box email during setup to use with Discourse. Mail-in-a-Box is an automatic self hosted email system where you run the script on a new Ubuntu 14.04 box with a dedicated domain name for email and it sets up everything for you and all you need to do is create email accounts and update the software regularly. I recommend it for managing your own email and it works for setting up an account for use with websites. I made and I use that to send email from websites. You aren’t dependent on any third party service if you host your own email.

I ran into a problem where I couldn’t get the first activation email so I activated my account manually. I successfully sent a test email from the admin panel so it looks like email will work now. I rebuild the app several times since then and I changed the nameservers used by the email box to what it looks like Mail-in-a-Box expects, so this might have helped mail delivery.


Cheap hosting for Mail-in-a-Box

Since one of the obvious goals of using Mail-in-a-Box is reducing expenses, it would make sense to host it on a very cheap hosting.

I initially wanted to use a 2.5$/mo VPS at Vultr. However, they refused opening SMTP ports, so I switched to a $5/mo DigitalOcean. Anyway, you’ll definitely want a dedicated VPS for your mail service.

Because that tiny VPS only has 512 MB RAM, you should setup a 2GB swap file before installing Mail-in-a-Box.

Dedicated domain name (cheap, too)

It’s advisable by Mail-in-a-Box to have a separate domain.

By comparing domain renewal and registration prices for various .TLDs at, I discovered one of the cheapest one is

.work $6.88
.space $7.88
.one $8.88 $5.69
.ws $8.88
.space $7.88
.bid $5.58 (5+ years)
.link $8.88 $4.88 (! cheapest)

Take into account that while registration price can be discounted, the regular renewal price may be high. So don’t forget to expand the “Renew” price section and search in there.

Please note with you won’t be able to setup DNSSEC, which improves email security, because this particular TLD (domain extension) does not support DNSSEC at the registry level (citing namecheap).

Step by step

Register domain name.

Create your new VPS, set its hostname to the domain name you just bought.

Check VPS’s IP against blacklists in MXToolbox. If blacklisted, destroy VPS and create a new one, and repeat until you find an IP that’s not blacklisted.

Mail-in-a-box can manage nameservers for you, but if you want to setup this way, first check whether your TLD requires two different IP addresses for nameservers, and whether you’re ready to purchase one more IP address. For instance, DO doesn’t allow more than 1 IP per droplet, so with a you won’t be able to get Mail-in-a-box to manage your DNS for you.

So, if you went this way, in your domain control panel, set two nameservers for the domain you just bought:

— Make both link to your VPS IP address(es). (instructions for

Finally, setup Mail-in-a-box and follow instructions as by the link. The automatic installation process may take 10+ minutes, especially on small VPS.

Multiple domains

Mail in a box may service emails for multiple domains.

So I’m slowly migrating all my small projects from using 3rd party mail hosting (sometimes not free) to my own Mail-in-a-box (free in terms of direct expenses, but not free in terms of my time spent on configuration and maintenance). Ask me in a private message if you want me to setup a dedicated mail-in-a-box for you in your VPS.


Note that you will still suffer from poor deliverability until systems learn to trust the IP you are sending from, which takes time and email delivery over a period of many months. And some systems will categorically never trust mail sent from shared hosting IP ranges.


Just wanted to update that after ~1.5 years, I’m still happy with Mail-in-a-Box, and deliverability is no longer a problem since the IP gained some good reputation thanks to the Discourse way to rate recipients.

I know very little about the “reputation” thing, but I suppose the longer you send no-spam emails from your IP, the better is your reputation.

Will keep using my dedicated $5/mo Mail-in-a-Box server - and using it for 3 forums now.


Thanks for this. I’ve been putting off running a mail server for several years now, but several things would be easier if I did. Glad it’s working out for you.


If others have this problem and i did too, setup a no cost mailjet account and verify your domain SPF and DKIM in your customer MiaB settings. You’ll still be able to use that notifications@ or even no-reply@ email in your Miab account yet for other hosted transactional emails for apps like Discourse, the credentials you get from Mailjet will work and reduce headaches on setups.

PS I think there have been situations where if I was really patient on the setup I could get the Miab settings to work but just want to help someone who might have used their self hosted email credentials and is still waiting for that final authentications email to complete install that never seems to come. When I’ve switched to my Mailjet user for that it shows up in a few minutes.


I use mailcow with our install of discourse and email delivers fine to 99% of the users. The remaining 1% being hotmail users and we suggest them to use some other email address.