How to force use DriveMail?

[Wolfgang Rosenauer]

You mean in a way that the user does not need to activate it or to disallow normal attachments?

You can force usage of DriveMail above a certain size:
com.openexchange.mail.compose.share.threshold=4500 0000

I'm not sure there is an out of the box way to select DriveMail by default in general.

[garybsimon]

Hi,

I want to figure out how to setup the auto usage of the DriveMail attachment service for all user.

How to setup DrivaMail as default attachment method for all email attachment and all user?

Please let me know.
Thank you.