What is the best way to see if your emails are heading to the spam folder?

[EmPaulin]

Now I am correlating open rates. but no real way to answer. 

This is after of course sending the campaigns/canvas to review the testing results. 

Also not spam reports / just when emails land in a spam folder. 

[luchilu]

The best way to check this would be using a third party system. Validity is a good one I've used at other companies. Inbox testing is Braze's out of the box feature that attempts to do this. I'm not sure how well it works, however it is good at helping you clean up emails that don't pass spam filters based on broken links or poor HTML.