Short Description: Enabled/Disabled shared mail
Specifies whether the shared mail feature is used for new mail delivered to this server:
0 - The shared mail feature is not used for new mail
1 - The shared mail feature is used for new mail delivered to this server
2 - The shared mail feature is used for new mail delivered to this server and for new mail transferred through this server.
When using the shared mail database (MAILOBJ.NSF), messages (Rich Text and Attachments) sent to multiple users on the same server will only be stored once. When set to 2, tells the server to use MAILOBJ.NSF for both delivery and transfer of messages.
For Lotus Notes/Domino 8.5 you should use then DAOS feature instead shared mail.
0 (shared mail not used)
Shared_Mail=0 / 1
There is no kown UI setting for this notes.ini variable. But you can specify this setting in the notes.ini settings tab of the configuration settings document.
Lotus Domino Administrator 5 Help
How to Enable Shared Mail in Domino 6