Is it possible to have Immediately when someone @mentions me in 'Email reminders' enabled by default?

Or enable it for other users as a site admin?

Hi Chris, 

It's currently not possible to enable it by default. However, the system admin has the possibility to configure email reminders for other users in the Administration - Users & Permissions - Users. Click on a username and choose the tab "Email Reminders". You can then activate the email reminder for @mentions for this specific user. 

Best regards
Samantha

Perfectly valid solution for me, thanks!