Forward = Spoofing?

[aseques]

HSorgYves Wrote:No, the error does not seem to come due to IP+SPF, but because they reject mail from: *@pt.lu which is not delivered through their mailserver.

Oh, I saw it now, "500 5.1.7 Spoofing denied", the server is not allowing mail from their domain originated externally, they are breaking forwarding functionallity.
One solution as I commented would be to use SRS (Sender Rewriting Schema), but altough it's almost the only solution, it doesn't have the approval of Wietse Venema from postfix.

HSorgYves Wrote:BTW for mailinglists it is working fine. Maybe I could just add some header (which one?) to get it working!

Could you post some extract of the headers of one of this mails? If the mailing list admin is sending it something like users@example.com there's no reason the sender should be blocked.

Cheers