joined:July 21, 2013
Over the years I have noticed many suspicious hits from hosts in the domain "your-server.de", such as attempts at accessing non-existing pages, especially blog admin pages (there are no blogs at all). OTOH, I can't recall ever seeing a genuine request from any host in that domain, so in my books they are just a spam provider, and I keep them tighly blocked.
The IP blocks associated with this provider are all listed here:
(I use the same method with other spam providers in countries that I don't want to block as a whole.)