Encryption: DEVONthink Pro Office - single or total database

Aforementioned within the manual on page 104.

Does anyone know the following:

  1. Encryption is based on single file or bulk database

  2. Emails encryption - encrypted locally on the device or also encrypted at recipient level.
    Example - I send an email, recipient receives encrypted email but can decode due to code being embedded within email. If email is removed from device/user the email still remain encrypted, improving security.