As the Org Admin you can choose to set mail approval rules for specific mail types. Doing this means all mails must be approved before they are sent.
Mail approvals can be set at an Organization or Project level, but only apply to your organization. You cannot approve mail sent from other organizations.
Project level mail approval rules will override organization level rules.
If you send a mail and you have been set as an approver for that mail type, it will be automatically approved and sent.
Click the Project tab to add an approval rule for this project only. It will override any organization level approval rules set for the chosen mail type. You must have permission to configure mail approvals for projects.