The Mailgun integration doesn't work when a domain has been setup in the EU region. It will only work if the domain is in the US Region.
We (and many other agencies) have clients all around the world, not just in the US.
When I asked Support why the EU region wouldn't work, I was told it was because of GDPR.
However GDPR Compliance should be left up to the company to ensure they are compliant, not be enforced by GHL.
Please change this so that domains setup in the EU region also work with the Mailgun integration.