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Mailbox.org custom email domain

Summary

How to add a custom domain email alias, including SPF, DMARC and DKIM records, to an existing mailbox.org email account. Simple step-by-step instruction to use your own domain with mailbox.org.

Edit DNS of your domain name #

Go to your 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:

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 Domain Name System (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 Exchange (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.

Check if the news DNS records have been propagated #

To check if everything is in place, you can open the console/terminal and use GNU dig tool to check the DNS configuation of your domain name.

Instead of example.com use your domain:

$ 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 #

Add a DomainKeys Identified Mail (DKIM) record with the following information to your domain names 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

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.

This is the official Mailbox.org DKIM key, you can copy and paste this example.

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 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.

Abbreviations #

Abbreviations used in this publication:

TTL
Time to live - a mechanism which limits the lifespan or lifetime of data in a computer or network.
DNS
Domain Name System - a hierarchical and decentralized naming system for computers, services, or other resources connected to the Internet.
DKIM
DomainKeys Identified Mail - an email security standard designed to make sure messages aren't altered in transit between the sending and recipient servers.
SPF
Sender Policy Framework - an email authentication method designed to detect forging sender addresses during the delivery of the email.
DMARC
Domain-based Message Authentication, Reporting, and Conformance - a standard email authentication method to prevent domain spoofing.

Further readings #

Sources and recommended, further resources on the topic:

Author

Jonas Jared Jacek • J15k

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

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/instructions/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.


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