Question about "Do not contact"

Your software
My Mautic version is: 4.0.0
My PHP version is: 4.7.33
My Database type and version is: MariaDB

Your problem
My problem is:
I wanted to learn about the “Do not contact” event thats triggered on contacts who unsubscribe.
If that contact is part of a Segment, next time when I launch a campaign for that segment, will Mautic detect and not send the emails to these contacts?

This is the first time I am using this so wanted to make sure I am not sending emails to those who have unsubscribed.

Thanks

These errors are showing in the log:

Steps I have tried to fix the problem:

Yes once a contact is marked as DNC they will no longer receive an email from the system, neither from a segment email or a campaign email.

Thanks a lot @mikew
Thats great to know.