Get "postfix-2.5.5-1.fc8.src.rpm" and and extract the files to your
RPM buildroot.
Get
http://vda.sourceforge.net/VDA/postf...da-ng.patch.gz and gunzip into ~/redhat/SOURCES/
If you did it all by the book then postfix.spec resides in ~/redhat/SPECS/.
Open it with any text editor and where it reads "Patch10: postfix-2.4.5-open_define.patch" add a line below reading "Patch11: postfix-2.5.5-vda-ng.patch", and where it reads "%patch10 -p1 -b .open_define" add a line below "%patch11 -p1", save .spec file.
Now build as usual with 'rpmbuild -ba ~/redhat/SPECS/postfix.spec'.
Should patch and build w/o probs.