Question Howto allow mails from t-online.de? (Domains without spf)

[obendev]

Hey, Deutsche Telekom Online Service GmbH is in strong believe that spf is something bad and they just won't add it for their t-online.de domain, which is their free mail service.
t-online.de Postmaster (See 3.5)
I already tried adding ip4:194.25.134.0/24 to my SPF local rules (Tools & Settings > Mail Server Settings > SPF spam protection), which would allow sending IP addresses of t-online.de (For example mailout01.t-online.de, mailout02.t-online.de, (...)), but turns out this doesn't work.
How do I handle this situation?
I've installed Plesk Email Security 1.0.5 with Medium threshold set and it sorts out mails to spam without a correct Received-SPF: pass

 

[obendev]

Now with Plesk Email Security 1.1.0-216 this seems fixed. I probably would've added SPF guess rules to get it to work, but there's no need for this anymore.