These instructions are for users who are hosting their domain on Cloudflare and would like to change their mail records (MX) so they can send and receive mail with Fastmail.
Note: Changing your MX records is the only way to use a Cloudflare-hosted domain with your Fastmail account, as Cloudflare automatically assigns nameservers to domains and these assignments cannot be changed.
This guide covers three steps to setting up your domain:
1. Add your domain to Fastmail
We have a setup guide to help you get your domain working as quickly and easily as possible.
After you have activated your domain at Cloudflare, log in to Fastmail and go to the Settings → Domains screen.
Add your domain(s) (e.g. mydomain.com). Click on the Add or buy domain button, then select the Use a domain you already own option. On the following screen, type in your domain.
If your domain is active at Cloudflare, we will display this on the next screen. You can also choose Cloudflare from our list of supported registrars.
Follow the domain setup wizard to add your email addresses to Fastmail. To have the domain wizard provide you with steps to update your MX records by default, choose Yes when you are asked if you have a website.
Please note: If you are on a legacy plan, the domain wizard can only set up email addresses, not users. You will need to add users manually in order to create additional user accounts at your custom domain.
2. Edit your MX records in Cloudflare
Note: We recommend making these changes at a time that you do not expect much mail to be sent to your domain.
1. Log in to your account at Cloudflare and find the domain you would like to use with Fastmail. In the menu at the top of the screen, click DNS, then Records.
2. Click Add Record, then choose MX for the Type.
3. Enter your MX record with the following details:
| Name | Mail server | Priority |
|---|---|---|
| @ | in1-smtp.messagingengine.com |
10 |
4. Then add a second MX record with the following details:
| Name | Mail server | Priority |
|---|---|---|
| @ | in2-smtp.messagingengine.com |
20 |
Leave the TTL as the default.
You should now have two MX records, in1-smtp.messagingengine.com and in2-smtp.messagingengine.com.
3. Signing your domain
Your domain should now be ready to receive messages. In order to make sure your sent messages reach your recipients, there are a couple more records to add in your Cloudflare account.
1. In your DNS control panel, click Add New Record. Add three new records, all with the type CNAME and the following information (make sure to replace mydomain.com with your actual domain name).
| Type | Name | Target |
|---|---|---|
| CNAME | fm1._domainkey |
fm1.{mydomain.com}.dkim.fmhosted.com |
| CNAME | fm2._domainkey |
fm2.{mydomain.com}.dkim.fmhosted.com |
| CNAME | fm3._domainkey |
fm3.{mydomain.com}.dkim.fmhosted.com |
You can leave any other CNAME records you have for your domain where they are.
2. For each record, under Proxy status, click the orange cloud icon so it turns grey. This will turn off CNAME flattening. Note: If you are on a paid Cloudflare plan, you may need to disable CNAME flattening for your domain by logging in to Cloudflare, navigating to DNS > Settings, and changing the dropdown that says Flatten CNAME at apex.
3. Click Add New Record again. In the drop down for the record type, choose TXT, then enter the following information:
| Type | Name | Content |
|---|---|---|
| TXT | @ |
v=spf1 include:spf.messagingengine.com ?all |
4. Click Add New Record again. In the drop down for the record type, choose TXT again, then enter the following information:
| Type | Host | Value |
| TXT | _dmarc.{mydomain.com} |
v=DMARC1; p=none; |
Once you have finished this step, your domain should be ready to use with Fastmail.
To check that all of your settings are correct, return to your Fastmail account and go to the Settings → Domains screen. Click Recheck DNS for your domain. Your domain should now say Active. MX records set.
Cloudflare has further instructions for using their DNS configuration panel available here.