Anyone know what a "504 Need Fully Qualified Address" is all about?
I sent a campaign to 200 public school teachers and the email was only delivered to 2 of them. Schools have notoriously overzealous email filters even for folks who have been approved to send emails (like my org). I chatted with their IT director and he said our email wasn't filtered by their system. My Googling around suggests that perhaps Marketo needs to set the hostname for its email servers.
I'm not an engineer nor am I an email server guru so I'm a bit lost for my next step.