Properties such as email deliveries, opens, and clicks (like all of the other properties in the Email Information contact property group) were initially intended to reflect only email sends via the HubSpot Marketing product. However, HubSpot hadn't been maintaining the counts in a way that captured that distinction; whenever HubSpot saw a send for an email address, the corresponding contact property count would be increased by one, regardless of which product sent it. So, as the CRM and Sales products gained more traction and more email sending volume, these values became more and more incorrect.
To correct this discrepancy, the HubSpot engineering team recalculated these values from scratch and migrated the properties to their corrected values. For some contacts, some or all of the properties were migrated to blank values because there were no events correlated to email sends via the Marketing product.
Note that only contacts which had counts "tainted" by non-Marketing sends had their affected properties migrated to corrected values; any unaffected contacts or properties won't have a migration entry in their property history.
Which contact properties were potentially affected?
- Emails Bounced
- Emails Delivered
- Emails Opened
- Emails Clicked
- First email send date
- First email open date
- First email click date
How will I know if a contact was impacted by this?
When looking at a contact's property history, you'll see an update to the affected property with the change source of Migration on or around August 7, 2017.