linuxconf is trying to do some permission management on files which do not belong to the packages the module was designed for. Example: if sendmail is removed and another mail transport agent is installed linuxconf is still trying to set setuid bit on execution for /usr/lib/sendmail , even this file now suppose NOT TO HAVE setuid on execution bit. set. Linuxconf should be modified in such way that if sendmail package is not install - do not manage any permissions on sendmail files at al. Same thing with the other sendmail modules. If linuxconf module suppose to manage package A then do not touch any files if package A is not installed, even if some of files have the same names as ones from package A.
Fixed in linuxconf-1.19r2-4. Linuxconf will no longer attempt to set permissions on /usr/sbin/sendmail, but I believe that the MTA should not be providing a binary with this name.
Every MTA (EXIM,QMAIL,SMAIL) provides a binary file /usr/sbin/sendmail for compatibility with sendmail. If they do not do this many programs (such as mailx, pine. etc) will stop working because they have the have /usr/sbin/sendmail hardcoded as mail transport agent.