The Emails by Contact report allows you to search archived emails based upon date range, contact name and the subject field, using the Filters option above your report.
The abilities to search the body of the message for keywords and phrases or to search by email address is not available in this report.
Please note that the Email Admin Viewing Permissions apply to this report - you can read more about Email Admin Viewing Permissions here (the relevant portion is the last section of the linked post). Only available to subscribers of Redtail's Email Archival and Retention Solutions.
To access the Emails by Contact Report, click the Reports option from your Left Menu Bar to see all of the available Standard Reports within your database:
Then, select Emails by Contact from the Email Reports box:
After clicking the report name, you'll see a report similar to the below (I've blurred email subject lines and from email addresses):
Note that the columns will allow you to sort the report data based upon that column's data by clicking the column name.
Above your report, you'll see several Options: