Add Fastmail email to your OfferingTree custom domain

If you have a custom domain on OfferingTree, you can use it for email as well as your website. Fastmail is one option, so if your domain is yogarocks.com you can send and receive as katy@yogarocks.com. Zoho and Google Workspace are other popular choices. Custom domains are included on all subscription plans.

Setting Fastmail up means adding a few DNS records: the ones that route your mail, and the ones that prove it really comes from you. If we host your domain's DNS, you can add all of them yourself on the Domains page.

Where your DNS records live

Go to Site Settings → Domains in your admin site. If your domain was bought through OfferingTree, or its DNS is hosted with us, you will see a DNS records section listing every record with an Add record button.

Two kinds of row are locked. Rows marked Managed by OfferingTree are the ones that run your website and keep its security certificate valid. Rows marked Email sending are for email OfferingTree sends on your behalf, and we manage those for you. Everything else, including the records below, is yours to edit.

If you do not see a DNS records section, your domain's DNS is managed somewhere else. Make the same changes there instead, using the guide for your domain provider.

Important: keep your DNS where it is

Fastmail offers to host your whole domain by taking over its nameservers. Do not choose that option. Your website's records live here, so moving the nameservers to Fastmail would take your site offline. When Fastmail asks, choose the option to manage your own DNS and add the individual records it lists.

Step 1: Sign up with your own domain

1. Create your account on the Fastmail signup page.
2. Choose to use a domain you already own and enter your domain name.
   
3. Complete registration and payment. Fastmail will then show you the DNS records to add.

Step 2: Send your mail to Fastmail

Add both MX records on the Domains page. Every MX record needs a priority, and a lower number is tried first.

Delete any MX records left over from a previous email provider. Mail follows whichever MX records exist, so leaving old ones in place will send some of your email to the wrong place.

Step 3: Prove your mail is really yours

These records keep your messages out of spam folders. Fastmail lists them in its custom domain DNS instructions, and they look like this:

• DKIM: three CNAME records on hosts fm1._domainkey, fm2._domainkey and fm3._domainkey, each pointing at the matching fm1.yourdomain.com.dkim.fmhosted.com value Fastmail shows you, with your own domain in the middle.
• SPF: a TXT record on host @, typically v=spf1 include:spf.messagingengine.com ?all. If your domain already has an SPF record, edit that one rather than adding a second. A domain may only have one, and two will fail.

Always copy the exact values from your own Fastmail account rather than typing them from here, since the DKIM values contain your domain name.

Mail usually starts arriving within a few minutes of saving, though DNS changes can take a few hours to reach everyone. Send yourself a test message once Fastmail reports the records as found.

A note on TTL

Leave the TTL at its default of 5 minutes unless Fastmail asks for something specific. It is the shortest we allow, and it means a later correction takes effect quickly.

Still stuck?

Email us at support@offeringtree.com with your domain name and what Fastmail is reporting, and we will take a look. For questions about Fastmail itself, such as billing, mailboxes or importing old mail, Fastmail's own support is the better place to ask.