[kronolith] Update 'To: Undisclosed Recipients'

[Wim]

In my Kronolith configuration I have configured.

Email address from which reminder emails should be sent : 
horde_reminder at domain.org

But when I add/delete an event I become my mail with in the from field : 
To: Undisclosed Recipients
When I receive an email from Kronolith Event Reminder I got it from the 
right address
Where do I have to configure that it is the same address when I 
add/delete an event????

Many thanks,