Check if a sugar user has the option "Notify on Assignment"

Hello,

I am working on a custom code and I need to know if a user has checked the option "Notify on Assignment" in his user settings.

In the Studio, I didn't find any field related to this setting. I only found its label : LBL_RECEIVE_NOTIFICATIONS:

I am able to retrieve the User bean, now I need a way to know if he checked or not this option. I didn't find relevant documentation about Users bean.  My last resort is directly querying the database but that's not very elegant.