Re-authentication on the CISS portal necessary.

Although the sender of an email has already been successfully authenticated to the REDDOXX portal, he still gets CISS Challenges when sending mails.
Or:
Although the sender is already in the Whitelist (AWL, DWL, SWL), a CISS Challenge is sent to the sender again.

In the configuration for AWL, the override of the negative filter CISS is missing.
 
Webinterface => Spamfinder => Filter Profiles
 
Select the appropriate filter (double-click) on tab "OVERRIDE".
In the positive filter "AWL" select and activate the checkbox for CISS in the right column.
 
The same applies to DWL and SWL.
 
Another cause may be that the validity date of filter entries (DWL, SWL) has expired.