How to set up on Mac OS X

The instructions and screenshots in this setup guide are for Mac OS X 10.11 (El Capitan). Previous versions of OS X are very similar, but may require more details to be entered manually. If you are using an older version of Mac OS X, you can find the information you might be asked for on our server names and ports page.

Setting up Mail

  1. Open If you do not already have any accounts set up, it will prompt you to set up a new account. Otherwise, go to MailPreferences and select the Accounts tab. Click the + at the lower left of the screen. Select Add Other Mail Account…

  2. Fill in your name, email address and password:

    • Full Name: The name people will see on the email you send.
    • Email Address: Your full FastMail username, including the domain.
    • Password: Your FastMail password.

  3. Click the Create button. The account will be created and will start syncing your mail.

If account creation fails and you are using a custom domain, you may need to explicitly set the mail servers:

Ensure the servers set to using password authentication, and use your FastMail email address and password to authenticate against the servers.

Adding your other email addresses

To use a different email address to your FastMail username:

  1. Go to MailPreferences and select the Accounts tab.
  2. Select your FastMail account on the left.
  3. Use the Aliases pop up menu to access your alternate addresses.

  4. Use the Edit Aliases option to add, delete or change your list of alternate addresses.

In MacOS prior to 10.11 (El Capitan), there is no aliases option. Instead, in the Email Address field, replace your FastMail username with the address you wish to use instead. You can also enter multiple email addresses, separated by a comma. If you do this, will let you choose which one you would like to use each time you compose a message.

Updating your password

If you change your password after adding your FastMail account to, you will need to update the settings in two places.

  1. Open From the menu bar, go to MailPreferences and select the Accounts tab.
  2. If you have multiple accounts set up, select your FastMail account in the list of accounts on the left.
  3. Under the "Account Information" section, focus the Password field, delete the current contents and type in your new password.
  4. Click the drop-down menu next to Outgoing Mail Server (SMTP) and select the Edit SMTP Server List… option.

  5. If you have more than one account set up, make sure you have the correct account selected at the top.

  6. Click the Advanced tab, then focus the Password field, delete the current contents and type in your new password.

  7. Click OK to close the SMTP dialog, then close the preferences window, saving your changes if prompted.

You should now be able to both send and receive mail again with your FastMail account. If you can do one, but not the other, try following the steps again carefully: your password may have been updated correctly for incoming mail, but not for outgoing mail, or vice versa.