RE: Tracking old emails to contacts
Hi louisa,
You can create a on-demand workflow in contact entity to create emails.
Then you can populate fields of the email with values you need, the most important is filling Bcc with dynamic value-current contact.
Then you can select contacts in the view to run the workflow.
Emails with theses contacts can be created automatically, and these emails will display in the timeline of corresponding contacts.
But the number of records returned by default is 50 in the view and maximum number is 250, you can go to Personalization Settings to set it.
If you don't want to change page, you can use Bulk Workflow Execution to run an on-demand for a view in the XrmToolBox, which can execute more than 250 records.
Run On-Demand Workflows on bulk records using XrmToolBox – bulk workflow execution - Microsoft Dynamics CRM Community