If your domain is setup with a cPanel hosting, log in cPanel, navigate to the Email section and click on the MailScanner icon.
If your domain is setup with a DirectAdmin hosting, log in DirectAdmin, navigate to the Extra Features section and click on the ConfigServer MSFE icon.
Click on MailControl
Once this page has loaded you will be able to view all mails received on the server. The mails that will have been blocked should be marked as High Spam. Click on the High Spam button to show all the mails marked as High Spam.
Find the email that was blocked and scroll over the Menu button and select Bulk Actions
This will open the checkboxes to allow you to select the email that you want released. Check the email you want released.
Once you have checked the email you want released scroll to the bottom of the page. Enter your email address and click on the Release (resend) button. Then repeat the above process by clicking on the Return button and selecting that email again then scroll to the bottom of the page and click on the Learn as Ham button in order to teach the filter to accept this email.