Mailbox.org custom email domain
Summary
How to add a custom domain to mailbox.org for sending and receiving emails. Includes instructions for SPF, DMARC and DKIM records, to an existing mailbox.org email account. Simple step-by-step instruction to use your own domain name with mailbox.org.
Edit DNS of your domain name #
Go to your Domain Name System (DNS) provider, where you can manage the DNS records of your domain name, e.g. example.com.
Select the domain on which you would like to set up your email address for mailbox.org, e.g. email@example.com.
In most cases, the DNS provider is the one you registered your domain name with.
Keep the window or tab open, you will need to return.
Add mailbox.org security key to your domain’s DNS #
In another window/tab, go to your mailbox.org account, usually at office.mailbox.org/appsuite/.
After you’ve logged in:
- Click on the cog wheel next to your user’s avatar, to open the settings.
- From the menu, select “mailbox.org”
- Then click on “E-mail Aliases” and then
- Select “Add external address”
There you can enter the email alias - email@example.com for your externally registered domain name, example.com.
Mailbox.org will generate a security key, a DNS record, which you have to add to your domain name’s DNS.
For example:
Domain name: 6acb2ba518998t894bbf11ec7724781ca6e5b210.example.com.
Record type: TXT
Value: 7ec7ec16a1d19c191613cbf741496d133f6e0014
Do not copy and paste the example information above!
Make sure to use the code generated by Mailbox.org for your email address.
Add Mail Exchanger (MX) records to your domain’s DNS #
Associate the Mailbox.org mailservers with your domain name by adding the following 3 mail exchanger (MX) records to your domain name’s DNS:
Domain name: example.com.
Record type: MX
Priority: 10
Value: mxext1.mailbox.org.
Domain name: example.com.
Record type: MX
Priority: 10
Value: mxextr2.mailbox.org.
Domain name: example.com.
Record type: MX
Priority: 20
Value: mxext3.mailbox.org.
These are the official Mailbox.org mail servers, you can copy and paste this example.
Some DNS providers abbreviate your domain name to @. So, if the domain name field is prefilled with @ you can leave this unchanged.
Add SPF records to your domain’s DNS #
Domain name: example.com.
Time to live (TTL): 3600
Record type: TXT
Value: v=spf1 include:mailbox.org
Some DNS providers abbreviate your domain name to @. So, if the domain name field is prefilled with @ you can leave this unchanged.
If you do not know what SPF is and would like to learn more, visit understanding SPF.
Check if the new DNS records have been propagated #
To check if everything is in place, you can open the console/terminal and use GNU dig tool (also see: dig cheat sheet) to check the DNS configuation of your domain name. Instead of example.com use your domain.
To check the mail exchanger records:
$ dig example.com mx
The result should like that:
example.com. 3600 IN MX 10 mxext1.mailbox.org.
example.com. 3600 IN MX 10 mxext2.mailbox.org.
example.com. 3600 IN MX 20 mxext3.mailbox.org.
To check the SPF record:
$ dig example.com txt
In the returned result, you should see an entry like that:
example.com. 3600 IN TXT v=spf1 include:mailbox.org
It may take a while, between a few minutes to 72 hours, for the DNS information to propagate worldwide.
DNS propagation is the time DNS changes take to be updated across the internet on the globe.
Generate Mailbox.org security code #
Go back to your mailbox.org account, where you’ve added the external email address. There you can generate the Mailbox.org security code.
Under “Add external address”, enter the email alias - email@example.com - once again.
Once Mailbox.org can access the newly added DNS information, adding your new external email address will be successful. You should see a green box, stating “Your external alias was added successfully.”
Add DKIM record to your domain’s DNS #
DomainKeys Identified Mail (DKIM) is an email authentication method designed to detect forged sender addresses in email (email spoofing), a technique often used in phishing and email spam.
The examples contain the official Mailbox.org DKIM keys.
You can copy and paste from the examples.
First key #
Add a DKIM record with the following information to your domain name’s DNS records:
Domain name: MBO0001._domainkey.example.com
Record type: TXT
Time to live (TTL): 3600
Value: v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA2K4PavXoNY8eGK2u61LIQlOHS8f5sWsCK5b+HMOfo0M+aNHwfqlVdzi/IwmYnuDKuXYuCllrgnxZ4fG4yVaux58v9grVsFHdzdjPlAQfp5rkiETYpCMZwgsmdseJ4CoZaosPHLjPumFE/Ua2WAQQljnunsM9TONM9L6KxrO9t5IISD1XtJb0bq1lVI/e72k3mnPd/q77qzhTDmwN4TSNJZN8sxzUJx9HNSMRRoEIHSDLTIJUK+Up8IeCx0B7CiOzG5w/cHyZ3AM5V8lkqBaTDK46AwTkTVGJf59QxUZArG3FEH5vy9HzDmy0tGG+053/x4RqkhqMg5/ClDm+lpZqWwIDAQAB
Back up key #
Domain name: MBO0002._domainkey.example.com
Record type: TXT
Time to live (TTL): 3600
Value: vDKIM1; krsa; pMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAqxEKIg2c48ecfmy/+rj35sBOhdfIYGNDCMeHy0b36DX6MNtS7zA/VDR2q5ubtHzraL5uUGas8kb/33wtrWFYxierLRXy12qj8ItdYCRugu9tXTByEED05WdBtRzJmrb8YBMfeK0E0K3wwoWfhIk/wzKbjMkbqYBOTYLlIcVGQWzOfN7/n3n+VChfu6sGFK3k2qrJNnw22iFy4C8Ks7j77+tCpm0PoUwA2hOdLrRw3ldx2E9PH0GVwIMJRgekY6cS7DrbHrj/AeGlwfwwCSi9T23mYvc79nVrh2+82ZqmkpZSTD2qq+ukOkyjdRuUPck6e2b+x141Nzd81dIZVfOEiwIDAQAB
Add DMARC DNS record to your domain’s DNS #
Add a Domain-based Message Authentication, Reporting, and Conformance (DMARC) record to your domain names DNS. DMARC is an email authentication protocol. It is designed to give email domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing.
Add two additional Email aliases, hostmaster@example.com and postmaster@example.com. Aliases for postmaster@, abuse@, hostmaster@ and webmaster@ are not counted towards to total allowed aliases. They are free with Mailbox.org.
Domain name: _dmarc.example.com
Record type: TXT
Time to live (TTL): 400
Value: v=DMARC1;p=none;rua=mailto:postmaster@example.com;ruf=mailto:hostmaster@example.com
Do not simply copy and paste this example! Make sure to put the email addresses you have created for rua and ruf.
Done #
That’s it, you can now use the Mailbox.org web client to send and receive emails as example.com.
To be able to use your new Email alias, with your favorite email client, you need to add it there, too. Manuals can be found in the Mailbox.org documentation.
Further readings #
Sources and recommended, further resources on the topic:
- Mailbox.org website
- Mailbox.org documentation - Using e-mail addresses of your domain
- Mailbox.org documentation - Custom domains
- Mailbox.org documentation - SPF, DKIM, and DMARC
- Mailbox.org documentation - Set DKIM entries
- DMARC.org website
- Understanding Sender Policy Framework (SPF)
- Understanding DomainKeys Identified Mail (DKIM)
- Understanding DMARC
- dig cheat sheet
Author
Jonas Jared Jacek (J15k)
Jonas works as project manager, web designer, and web developer since 2001. On top of that, he is a Linux system administrator with a broad interest in things related to programming, architecture, and design. See: https://www.j15k.com/License
Mailbox.org custom email domain by Jonas Jared Jacek is licensed under CC BY-SA 4.0.
This license requires that reusers give credit to the creator. It allows reusers to distribute, remix, adapt, and build upon the material in any medium or format, for noncommercial purposes only. To give credit, provide a link back to the original source, the author, and the license e.g. like this:
<p xmlns:cc="http://creativecommons.org/ns#" xmlns:dct="http://purl.org/dc/terms/"><a property="dct:title" rel="cc:attributionURL" href="https://www.ditig.com/custom-domain-email-alias-mailbox-org">Mailbox.org custom email domain</a> by <a rel="cc:attributionURL dct:creator" property="cc:attributionName" href="https://www.j15k.com/">Jonas Jared Jacek</a> is licensed under <a href="https://creativecommons.org/licenses/by-sa/4.0/" target="_blank" rel="license noopener noreferrer">CC BY-SA 4.0</a>.</p>For more information see the Ditig legal page.
