This and many other questions are answered in the Majordomo FAQ.
> I installed Majordomo-1.94.4 on my Linux Redhat6 system, and no
> errors or warnings were encountered during the installation and
> Permissions, etc. seem fine, but when I send a "lists" request to
> majordomo, the following message is sent to "majordomo-owner"
> from "MAILER-DAEMON".
> Mail Delivery Subsystem <MAILER-DAEMON@linux.so.de.co.za>
> ----- The following addresses had permanent fatal errors -----
> "|/usr/local/majordomo-1.94.4/wrapper majordomo"
> (expanded from: <Majordomo@linux.so.de.co.za>)
> ----- Transcript of session follows -----
> sh: wrapper not available for sendmail programs
> 554 "|/usr/local/majordomo-1.94.4/wrapper majordomo"... Service
> The wrapper permissions are:
> -rwsr-xr-x 1 root daemon 14882 Jan 7 10:55 wrapper*
> Perl version is 5.005_03 built for i386-linux.
> Any idea please??
> Many thanks!!
> Jasper Hoon