Setting up your domain: no NS/MX

There's just three simple steps:

  1. Add your domain
  2. Apply DKIM and SPF records
  3. Add email addresses at your domain

Optional set up

1. Add your domain

  1. Go to the Settings → Domains screen. .
  2. Add your domain(s) (e.g. Using the "Add Domain" button brings up the new domain screen. Type your domain into the text box.

    add domain page in UI

Fastmail will report the domain is "Not yet active. Waiting for DNS change." Since your domain isn't hosted with Fastmail and the DNS records do not point to Fastmail, this warning will remain.

2. Apply DKIM and SPF records

You will need to set the DKIM and SPF records with your domain server to ensure your mail is properly signed.

  1. Go to the Settings → Domains screen and follow the Show DNS settings link.
  2. Find the three CNAME entries for DKIM. These will need to be copied into your domain registrar's DNS control panel.
    • The ones with the names of fm1._domainkey.<yourdomain.tld>, fm2._domainkey.<yourdomain.tld> and fm3._domainkey.<yourdomain.tld> are DKIM entries.
  3. Find the TXT entry for SPF. This also needs to be copied into your domain registrar's DNS control panel.
    • The one with the value of v=spf1, <text> is for SPF.

3. Add email addresses at your domain

To set up email addresses for your custom domain, add aliases at Settings → Users & Aliases. Add as many as you need. You may also choose to add a catchall alias so 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 matching that alias. You can customize other settings too, such as your signature.

If you'd like to set up your account so mail is sent from one of your custom domain addresses by default:

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

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.

subdomain set up

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: