I have a contact, company or project blog showing emails that are not related to that record.

Ensure the data you are linking on is specific enough to produce good results. Refine the filtering criteria in the linked-email activity by hovering your mouse over the activity, clicking on the edit icon.

Since project blogs default to filtering on the Title field and do not have an email address you may need to use a deliberate pattern to ensure the emails link to the page as expected. Adding a special character such as a [ # ] with a project code is a best practice.