[Mailman-Users] wrapper not available for sendmail programs?

hello all,   i've installed mailman, it seem working fine until i send a message to my mailing list, then i got this error message back, =   - The following addresses had permanent fatal errors -"|/home/mailman/mail/wrapper post mylist2"    (reason: service unavailable)    (e

[Mailman-Users] (mailman) -- Failure to exec script.

hello all, i'm tring to install mailman on RH7 linux,sendmail, during installation everything seemed fine, but when i go to website, got this message, what am i doing wrong? i thing it's something to do with cgi. but what? Failure to exec script. WANTED gid 500, GOT gid 99. (Reconfigure to take