Description: This solution discusses how ImportOmatic auto-picks to an email on a constituent record
ImportOmatic can auto-pick a record based on the email.
The email will need to be mapped to Record Type = Constituent Email - Address and the Value Type = (Selected Email Type)
In the left side navigation pane, go to Duplicate Search and check the box to "Perform a duplicate search when a record cannot be matched by ID".
Next, highlight Auto-pick. Check the box to "Auto-pick record from search results if a single record exactly matches" : Select Email.