Why do statistics under VR Email History appear inaccurate for my Leads or Contacts?

The Salesforce History option to update Leads and Contacts must be checked when to launching your email message. When an email is launched, all persons on the list(s) associated with your email will then be marked with a status of Sent under the VR Email History object. If this option is not checked prior to launch, this information will not be updated and your statistics will not be accurate. (note:  if your list was created from a Campaign then Campaign History rather than Activity History will be updated).
 
As the Sent status is updated for all members of a list it is possible that someone who unsubscribed from a prior mailing, but who is still present on a list, may be marked as Sent under the VR Email History object. The email will not be sent to anyone who has unsubscribed through VerticalResponse but this may account for reporting discrepancies.
 
Following the launch of the mail you can click the Update Salesforce Statistics button found in email report under VR Statistics. Any recipient who responded (a click, open, bounce or unsubscribe) will be updated under in the VR Email History within Salesforce. You will not have a count of Non-Responders (those mailed to who took no action) unless the Salesforce History option to update Leads and Contacts option was checked upon launch.