You can block or allow pop-ups based on three filter levels: High Block All Pop-ups Medium Block most Automatic pop-ups Low ...

You can block or allow pop-ups based on three filter levels:
    High – Block All Pop-ups
    Medium – Block most Automatic pop-ups
    Low – Allow pop-ups from secure sites.

If you enable this policy, users will not be able to change the filter levels. You can specify the pop-up filter level by importing Privacy settings from your machine under Internet Explorer Maintenance.

If you disable or do not configure this policy, users will be able to manage pop-ups based on the filter levels.

You may also want to enable "Turn off Managing Pop-up Allow list" and "Turn off Pop-Up Management" policies to disable users from configuring pop up behavior.