Sounds a bit odd: you finally get the ability to set a default font for mails in the Notes Client starting with version 8.5.2 — and then you want to disable this feature again?
It may well be that the font has already been defined in the mail template and a company wants to prevent every user from choosing a different font. In such a case, disabling the setting option in the client can make perfect sense. So – how is it done?
No default font configuration: using a NOTES.INI parameter
By adding the NOTES.INI parameter
DisableSetMailFont=1
you can disable the "Set Current Font as Mail Default" option in the "Text" menu of the Notes Client. This menu item will then no longer be available in the Notes Client.