If you open an email and see the Enhanced View pop up it means that the app didn't processed it before opening it.
We’re displaying the original mode until the email is indexed or processed in order to avoid delays in Email display.
This shouldn't happen often since we are indexing all synced emails after syncing them on the device. BUT if we have a big group of newly incoming emails, or if the email is old, we will process them slowly in order to save battery.
Appearance of "Enhanced View" pop up could happen in the following cases:
1) You open new email too quickly (i.e. before it was indexed, or processed)
2) You synced a big group of emails (you had a big inflow of emails in a given time)
3) The opened email is an old email (we give lower priority to indexing/processing older mails)
In case you run into this issue in other cases, or if you see the pop up too often - please let us know as it might be a bug in our indexing process.