Mailgun setup fails certificate validation

While setting up Mailgun with either:


Returns the following error while sending a test email:

gomail: could not send email 1: StartTLS: x509: certificate is valid for *,, not

Seems like a bug in validation, since * is a wildcard that covers

I just now realized that it’s a different TLD :man_facepalming:

For folks who came across this, just use the correct smtp server host: