Sorry about the last mail, my spam filter declared my outgoing mail as spam as well.

This is what my mailserver detected when it analyzed your mail:

8.5 URIBL_SBL              Contains an URL's NS IP listed in the Spamhaus SBL
                            blocklist
                            [URIs: m ail.f ink.o rg]

Maybe Swisscom/Bluewin does kind of the same, just call it differently?

Note I added some whitespaces into the domain.