Log in to your Mailgun account and your GoDaddy (or other DNS provider) account.
Select the domain you want to use for Mailgun from your GoDaddy account. You will set-up a subdomain for Mailgun so it's ok to choose a domain that is being utilized elsewhere.
Navigate to your Mailgun account, select Domains from the menu at the top. Then click Add New Domain.
Create a subdomain such as replies.yourdomain.com or mg.yourdomain.com and enter it in the Domain Name field.
You can leave all other settings as default.
Click Add Domain
In Mailgun, you will see the DNS entries; 2 TXT records, 2 MX records, and 1 CNAME. Go back to GoDaddy DNS provider. Now you will set up the DNS entries.
Choose Type from the dropdown menu to add the DNS entry.
Here are the record types shown in Mailgun. NOTE: Do not use these exact record hosts as they the hosts will be specific to the domain you are setting up.
Type: TXT ; Host: replies ; Value: paste from Mailgun page. Save
(Repeat for 2nd TXT record.)
Type: MX ; Host: replies ; Points to: paste from Mailgun page ; Priority: 10 ; TTL: leave defaulted to 1 hour.
(Repeat for 2nd MX record.)
Type: CNAME ; Host: email.replies ; Points to: enter value ; TTL: leave defaulted to 1 hour
All 5 should have the green check mark. If any do not, check the record and re-attempt.
NOTE: If the green check marks are not showing up, you'll want to ensure that the Host pieces for each record only have the sub-domain piece of the total record. For example, if the total record is mailo._domainkey.mg.thedemoaccount.com, you would only put in mailo._domainkey.mg.
