Most email addresses use the default domain provided by their email service. For Proton Mail accounts, it’s For Gmail, it’s These are usually free and work just fine for most people.

But there are situations where it makes sense to switch to a custom email domain. For example, if you’re running a business, starting a club, or building a personal brand, you may want to get a custom email domain to improve your organizational security and reputation.

This article covers everything you need to know about custom email domains, including how to set one up and some benefits of using a custom domain that you might not have considered.

What is an email domain?
What is a custom email domain?
Why use a custom email domain?
How to get a custom email domain
How to choose a custom domain for your email
Benefits of using a custom domain in Proton Mail

What is an email domain?

Email addresses have two parts, separated by an @ symbol. The first part is the username. The second part is the email domain (for example,

The domain helps identify which server to route incoming emails to. So when you send an email to, your email provider knows to route the message to a Proton Mail server. The username identifies which account to deliver the email to within that server.

What is a custom email domain?

A custom email domain is a personalized email domain that you own. Some email services let you swap out their generic domain for your own domain. For example, may point to a Proton Mail server, a Gmail server, or even a private email server you own. Emails still know where to find you thanks to a routing system on the internet that takes place behind the scenes.

Domain names are a memorable shorthand that help route traffic on the internet. Your email domain is associated with something called an MX record (mail exchanger record), which points to a mail server.

Below we’ll show you how to get a custom domain and connect it with MX records for a few popular email providers.

But first, let’s look at some of the benefits of a custom email domain.

Why use a custom email domain

Custom email domains are most common among businesses, but they also offer benefits to small organizations and families. Here are some of the most common reasons to use one:

  • Freedom to change providers — With a generic email domain like, you’re tied to that email service. If you want to switch to a new email provider, you have to get a new email address. Custom email domains allow you to switch to a new provider without giving up your email address.
  • More organizational control — If you own a custom email domain, you can choose who uses email addresses associated with that domain. Your employees’ email addresses belong to you, and you can assign or revoke them as needed.
  • Better email addresses — Generally speaking, people with generic email domains have already claimed all the best usernames. But if you own a custom email domain, you can create email addresses like or 
  • Look professional — If you’re applying for a job or building a personal brand, a custom domain can be more memorable and professional than the email address you’ve had for decades.
  • Stronger security — You can maintain better cybersecurity if it’s easy to recognize emails coming from inside your organization. For example, if a colleague sends you a link or an invoice you weren’t expecting from a email address, this is an immediate red flag that a hacker may be impersonating someone to hack you or commit fraud.

How to get a custom email domain

There are two main steps to setting up a custom email domain. If you don’t already have your own domain, you’ll need to buy one from a registrar and connect it to an email service provider. 

1. Purchase a domain from a registrar

If you already own a domain, you can skip this step. If not, you’ll need to buy one. There are many companies, known as registrars, that sell domains. Cloudflare, Bluehost, Namecheap, and GoDaddy are among the most popular.

The domain registrar will let you look up available domains, pay for them online, and manage them from your account dashboard. Once you’ve set up your domain, look for the DNS panel in your account. You’ll need that for the next step.

Need help choosing a domain? Scroll down and check out our section below for tips.

2. Connect your domain to your email service provider

Here’s how to connect your domain to your email account for a few of the most popular email providers, including ours. 

Important note: We’ve only included simplified instructions here. Be sure to read the support pages for detailed instructions on connecting your domain and adding additional security-related DNS records to prevent spoofing and phishing from your email address.

Set up a custom email domain in Proton Mail

  1. Sign up for a Proton Mail Plus, Proton Unlimited, or Proton Business(new window) plan.
  2. Go to and click Add domain. Then add your Proton Mail DNS records to your DNS console in your domain dashboard.

For detailed instructions, visit our Support article on custom domains.

Set up a custom email domain in Gmail

  1. Create a Google Workspace account and then create a user account for each new email address under your organization.
  2. Add the MX records for Gmail to your DNS console in your domain dashboard. 

For detailed instructions, visit Google’s help page(new window).

Set up a custom email domain in Outlook

  1. In your Microsoft 365 account, add a user account and a mailbox for everyone who has an email account on your domain. 
  2. Microsoft lets you purchase domains from its platform or connect an existing domain. To connect an existing domain, you’ll need to verify that you own the domain by clicking a verification button or adding verification records. 
  3. Sign out of Microsoft 365 and then sign back in with the new email address. Your employees can now also sign in with their new email addresses.
  4. If you connected an existing domain, you will now need to add the MX records from Microsoft to your DNS console.

See detailed instructions in Microsoft’s help center(new window).

Don’t forget to add anti-spoofing(new window) records to your DNS panel for your custom domain. Learn more about SPF, DKIM, and DMARC records.(new window)

How to choose a custom domain for your email

If it’s your first time picking a custom domain, you might not know exactly where to start. Oftentimes, the perfect domain is already taken. Here are some ideas to help you pick the right domain for your email address:

  • Keep it short — When it comes to domains, shorter is almost always better. You want your domain to be memorable, easy to type, and difficult to mess up. Remember, you may need to communicate your email address to someone verbally at some point, so you’ll want to choose something easy to spell out.
  • Avoid special characters — Like strange domain extensions, special characters can be an indication of spam or phishing. Try to keep it to letters only.
  • Consider your budget — There are still a lot of great domains available, but they’ll cost you. The best domain for you might cost a few thousand dollars. You’ll need to determine whether the return on investment is worth it for the domain you choose.

Benefits of using a custom domain in Proton Mail

Proton Mail is the world’s largest email service that uses end-to-end encryption by default. If you’re looking for an email service to park your custom email domain, Proton is the only major provider that offers our level of security and privacy as well as essential features for businesses and professionals.

When you upgrade to a premium Proton plan, you’ll not only get access to custom domains, you’ll also unlock our entire encrypted suite of services. This includes our calendar, cloud storage service, VPN, and password manager. All of our tools use end-to-end encryption by default, meaning nobody can see your data except you. 

Unlike Gmail, Outlook, iCloud, and other services, Proton can’t see the contents of your emails, calendar events, or files in the cloud.

Founded in 2014 by scientists who met at CERN, Proton is based in Switzerland, where your data is protected by strong privacy laws. We believe security and privacy should be the default online, and we’ve built Proton Mail to offer a unique combination of features that sets us apart from all other providers. Our encrypted custom domains offering is one of them.

Proton Mail Plus plan lets you connect one custom domain. Proton Unlimited includes support for three custom domains. Learn about our Plus and Unlimited plans.

Among our professional plans, the Mail Essentials plan lets you connect three custom domains, and our Business plan includes support for up to 10 custom email domains. Learn about our Business plans.

You can also try out Proton Mail for free and start protecting your emails today.

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