Updating TXT records in Namecheap for Mailgun domain verification
To verify the domain, Mailgun requires the addition of at least two TXT records with specific values. However, if you add the TXT records in Namecheap exactly as specified by Mailgun, Mailgun will not be able to verify the domain, and you won’t be able to send email from your application. :(
If you owned yourdomain.com, Mailgun suggests adding two TXT records with the host entries mg.yourdomain.com and mx._domainkey.mg.yourdomain.com. For Traitlab, those looked like this:
What Mailgun says you need
Instead, drop the yourdomain.com from each host entry, so the resulting entries are simply mg and mx._domainkey.mg. In your Namecheap DNS settings, it should look something like this:
What you actually need in Namecheap
After making this change, Mailgun was able to verify the domain in a few minutes!