In Recruiterflow, you have the option to unsubscribe a candidate's/contact's profile.
Once you unsubscribe from a profile, all the communication on that profile will be stopped till you go back and subscribe to that profile again!
Advanced search can help you take out a list of all the candidates/contacts that have been unsubscribed.
Go to Advanced search
Select if you want to search through 'Candidates' or 'Contacts',
Add the filter: Profile status
After you select 'Profile status' it will show you a dropdown under which you can select 'Unsubscribed'.