Mailgun and Squarespace DNS settings
Ghost uses Mailgun for email sending and essentially all things related to user management.
In order to get Mailgun to work, you need to set up the DNS settings for your custom domain. These settings are listed under Sending on the Mailgun dashboard:
My domains are registed with Squarespace and these settings can be added on the DNS settings page.
Mailgun provides DNS settings for the custom domain that you set up, but these are not completely accurate when copying and pasting into Squarespace.
For this example, let’s assume that you’re using m.example.com as your custom domain.
You’ll see that there are six additional records that you need to add to your Squarespace DNS settings. The key thing is to remove references to the main domain name from the records. For instance references to m.example.com should be removed and replaced with just the “m” subdomain.
Once you’ve added these records, you should be able to save the settings and then verify
the settings on the Mailgun dashboard.