The only thing that was any problem was getting outgoing mail working. I hadn't set up SMTP authentication previously. And as far as I could tell, Mandrake 10.0 (which is what I'm still using) simply didn't provide the right SASL libraries to work with Postfix. Or they were in the wrong directory. Or something. (The mix of 64 and 32 bit binaries is always a mess.)
I solved the problem my compiling the latest versions of Cyrus SASL and Postfix from source, and the new versions cooperated more nicely.
