hi ,
iam not sure but there is some option called --prefix which allows u to relocate the s/w to user defined directory ( if possible) ...
so first check out !
for example
rpm -qp --queryformat "%{defaultprefix}\n" sendmail-1.rpm
and if u see some path
/usr/bin
then execute :# rpm -i --prefix /tmp/test sendmail.rpm
i hope this works for u.
regards,
xanthium.