Making popclient setuid root removed that error, thanks very much. There are potential problems bout making something setuid root, however, and I wonder if it isn't a bug in popclient that it doesn't internally obtain the right priveleges when setting the biffbit. What do others think?
------- FYI, "chmod u+s" makes an executable file "setuid", which means as you say, that it runs with the priveleges of the file's owner. There is an equivalent "g+s" which makes an executable run "setgid", that is, with the priveleges of the file's group. Making anything setuid root poses a security risk, since sometimes the priveleges of these programs can be turned to destructive purposes with sneaky tricks that as a matter of policy aren't publicized by the gurus who know about them. In some ways, these facts pertaining to file permissions are very basic Unix, but there are some subtleties. I have used Unix for almost 8 years without understanding why a shell script that is setuid userX can't read or execute a file that only userX can read or execute. The expected thing happens, however, with setgid scripts. There is in general a complication in that the system keeps track of "effective" and "real" user ids, and you can't change your real user id without a C program. Thanks for your response. If you have any questions about file permissions, let's take them offline, I'd be happy to try to answer them. Matt
