Mh that one didn't made it to me. Will look into it. In my cases, the fallback worked, tho. Mail just did get delivered without any trouble. I'll test this some more.
I briefly compared your changes to the spamc code, and noticed that your code did not have any FALLBACK support. vdelivermail would crash, and qmail-local just returned the message to the queue. I stopped investigating it at that point.
Furthermore, what do you guys think about having it per user configureable (with like a .usespamassassin file in Maildir)? Any chance to see such a setting incorporated into qmailadmin (not very useful if qmailadmin doesn't support it itself)? Maybe I should provide lib functions to read and set it?
What is the normal filename? I only implement it site-wide. Also, I thought I remember spamassassin having limited vpopmail support. Is that still the case? If so, how is this better than that implementation?