Email open & bounce stats
There is an expected lag of a few minutes between when an email is opened and when that open is recorded in your account. We handle logging asynchronously, which means when you send an email, we aren't trying to log data during the send process and potentially disrupting or slowing that down.
Furthermore, once we get the open, we need to associate with your account and add it to the searchable index for your account/messages which can take some time. Since opens and clicks are background processes, they're essentially secondary or tertiary to other processes like sending, and can slow down if we have a sharp uptick in primary processes or a large percentage of open and click activity coming in at one time.
All that said while we do expect sending data to be updated within a few minutes, but it is possible to see a delay at times.