Advanced Settings & Options Panel
RPost allows the sender to adjust and set default system features in Outlook for a customized experience.
Access to the options are from the following locations:
Outlook 2016 Desktop
The “Advanced Options” button on the Feature Panel pop-up.
Outlook 2000, XP & 2007:
Tools > Options > Registered Email (tab) > Options
Outlook 2010, 2013:
File > RPostOffice Email Options