When I export the send results into a spreadsheet, sort by activity type and find the sum of each activity, not all of the numbers match the numbers provided in the email performance report in the analytics section. In the instance I'm looking at now, it's the Delivered and Opened numbers particularly.
1. Regarding the mismatch in Delivered numbers - Please refer link - Difference in Marketo Email Reporting Metrics
2. Regarding the mismatch in Opened numbers - Opens are counted when the email recipient downloads the email's images, which includes a Marketo-inserted tracking pixel. If the recipient views the email but chooses not to download its images, that will not count as an open. If the images load in the recipient's preview pane, that will usually count as an open, but it will vary based on the email client.If they have images blocked or if they read the email in a preview pane, we won’t be able to track that as an open. Now, if someone who has images blocked clicked on the email. Logic would dictate to us that they must have opened the email also. Our Email Performance Report has this logic built in. The activity log does not. So there will be no Opened Email activity recorded in the person’s activity log, but the report will count them as having opened. Hence the mismatch.