cant compile sqwebmail

[hostmaster]

any body help please we are using 4.1 BSDI  wenn i compile sqwebmail
iam getting the following error. thanks for the help advance.
matrix:~/webmail/sqwebmail-0.36.37pre2#./configure
checking whether -lnsl is needed for inet_addr... configure: error: Cannot
find
function inet_addr
configure: error: ./configure failed for authlib