Setting up your domain: NS/MX

With this option, we host your DNS and automatically make sure the rest of your DNS is set up correctly. All you need to do is point your nameservers to us — we take care of the rest.

We provide a control panel for full customization of your DNS records if needed. Our nameservers are fast, reliable, and secure, and you can easily manage your DNS through our simple, but powerful, interface!

There's just three simple steps to set up your domain:

  1. Add your domain
  2. Update your NS records
  3. Add email addresses at your domain


Optional domain set up

We have handy guides for setting up your domain's nameserver records with a few common domain registrars:

1. Add your domain

We have a setup guide to help you get your domain working as quickly and easily as possible.

Go to the Settings → Domains screen. Then, add your domain(s) (e.g.

Clicking the Add Domain button brings up the new domain wizard. Type your domain into the box. We will detect whether your domain has been registered or not. It's important that the domain has already been registered by you at a domain registrar; otherwise you won't be able to make the necessary changes.

Follow the on-screen prompts to continue adding your email addresses and setting up your domain. At the end, we will generate the instructions that match your situation. The general instructions for editing your nameserver records are below.

Please note: The domain setup wizard can only set up aliases on legacy plans. If you are on a legacy plan, you will need to add users manually in order to create additional user accounts at your custom domain.

2. Update your NS records

Note: Updating your DNS can take some time: we recommend updating it at a time you don't expect many emails.

3. Add email addresses at your domain

Email addresses for your domain are added during the domain setup process. If you need to add additional email addresses at a later date, these can be added in the Settings → Users & Aliases screen. You may also choose to add a catchall alias if one was not already set up with the domain, so that any mail addressed to your domain comes to you, no matter what address is used.

Creating an alias also creates a matching account identity. This lets you send mail from your account using the email address. You can customize other settings too, such as your signature.

If you'd like to set up your account to send using one of your custom domain addresses by default:

  1. Navigate to the Settings → Sending Identities screen.
  2. Select your address in the "Compose new messages from <address> by default".


Depending on the TTL values for your previous DNS settings (if any), it may take up to a day for the changes to propagate across the internet. Normally it's a lot faster: just a matter of minutes. Messages sent to the addresses you added on the aliases screen should now arrive in your Inbox.

Optional domain set up

System email addresses

The email standard requires that the email address be a valid email address. Because of this, even if you don't set up an alias for that address, we will deliver any email sent to that address to the owner of the domain.

It's also best practice to support By default, if you don't set up your own alias for, we'll automatically direct all email sent to to our abuse handling system.

Subdomain addressing and mail routing

On the Settings → Domains screen, you can control subdomain addressing and mail routing.

The Mail: Subdomain section lets you control how Fastmail handles subdomain addressing for your domain. There are three options:

The Mail: Routing section lets you choose how mail to this domain is handled. Use: