Getting our email valid and off the spam list

We have a decent sized opt-in email publication. We are now getting sent to everyone's spam folders and often not even getting to the end user. We are looking for someone that knows about keeping an email compliant and off the spam list, since we absolutely don't spam. The change did seem to align with us moving to a Microsoft based email provider through Godaddy.

So that's it. We need someone to jump through the hoops and free our email. Thanks!