Email Performance Report stops collecting data after 2 days?

Hello all,

I filed a ticket with Support recently, because we saw a discrepancy between the number of clicks in an email performance report vs. in a Smart List with a "Has Clicked Email" filter on the same email. And here's what Support said:

"The reason you're seeing this behavior is because Email reports stop collecting data after 48 hours after the send. So this means if someone was sent the email and they opened it 3 days later, even though this will show up in the lead activity it will not be collected into the report in Marketo."

Is that true? I asked for documentation on that statement, and so far they haven't come back to me.

Thanks!
Michael