When sending mail from MailGun, I get "Sender address rejected: Domain not found"

I have 2 domains setup in Mail In A Box, but I am unable to send mail to them using MailGun. any other provider seems fine .e hotmail.com

Error: “Sender address rejected: Domain not found”

Any ideas?


perhaps you forgot to add their custom DNS?

  1. to merge its SPF with the default one into your ‘custom DNS’ panel for your domain:

yourdomain.com TXT v=spf1 include:mailgun.org ~all

  1. to add their TXT DKIM record to your ‘custom DNS’ panel for your domain