Since we integrate with your existing email provider this information exist in your email system as we have no control on how a prospect behaves with your email once it is sent.
If you are using Google as your provider (Gsuite) you should consider registering for Google postmaster (it is free) which gives you the ability to better understand your sender reputation as well as spam complaints.
Having too many people mark your email as spam will lead to a negative sender score which can affect your inbox placement and overall deliverability.
Here are some actions you can monitor to identify if emails are landing in the spam folder.
Mainly, look at open and click statistics and compare recent data to past data. Does it look like opens and clicks took a dip? If so, there is a good indication there that your messages are either going to the spam folder or bouncing.
Monitor all negative engagement signals - Bounces, Delivery failures, Heavy Opt out rates ( a sign of wrong targeting profile), these will give you a good indication as to why you are not reaching the inbox folder, or what is causing the problems that you are currently facing.
You can always diagnose your email domain by reviewing the steps in this article to improve email deliverability.