There are several mail flow reasons that this could be happening, but if you're seeing the emails pass through Mailprotector and the recipient still isn't receiving them, the recipient is blocked in Bracket.
In these cases, please select "Submit a Request" and tell Mailprotector support that a recipient is possibly on the suppression list. We will check the list of suppressed users and either inform them or troubleshoot your issue.
Please reference an email if you submit a support request. This will help us resolve your issue quickly.