FPs due to dd.*\.kasserver\.com

[xrat]

I have only recently started to use fqrdns.pcre and quickly found some domains/senders causing FPs due to

/^dd[1-9][0-9]{3,5}\.kasserver\.com$/ REJECT Generic - Please relay via ISP (kasserver.com)

In many if not all cases the IP addresses + the FQrDNS names have been stable over the course of several months (I checked my logs since January 2019). The domains with the highest volumes are

seiteanseite.at 85.13.147.26 dd28616.kasserver.com
wohlrab.at 85.13.145.46 dd26118.kasserver.com
mailman.pxldsk.com 85.13.153.66 dd36426.kasserver.com
kindertheater.com 85.13.145.208 dd26926.kasserver.com
drehbuchforum.at 85.13.133.140 dd10926.kasserver.com
fluglaerm.at 85.13.152.9 dd34912.kasserver.com
concordia.at 85.13.130.23 dd3712.kasserver.com

EDIT: Found not just 2 but several more FPs.