How to turn off conversation threading in Lotus Notes

In Lotus Notes 8.x client, you have to use:

File -> Application -> Properties Advanced (tab)

and then uncheck "Support Response Thread History"


In Lotus Notes client

File -> Database (mail database) -> Properties -> Advanced (tab)

un-check "Support Response Thread History"

or

In Mail Database

Click on "Show" button -> Individual Messages


IBM Notes 9: Social Edition

Turn off conversations

Actions -> Individual Messages (Alt + A + I)

Turn on conversations (mail grouping)

Actions -> Conversations (Alt + A + R, R, Enter)