postfix installation

following the instructions, I get these error lines: cc -I/usr/local/include -g -O -I. -I../../include -DRHAPSODY5 -o master master.o master_conf.o master_ent.o master_sig.o master_avail.o master_spawn.o master_service.o master_status.o master_listen.o master_vars.o master_wakeup.o master_flow.o ../../lib/libglobal.a ../../lib/libutil.a -L/usr/local/lib -ldb -flat_namespace ld: can't locate file for: -ldb make: *** [master] Error 1 make: *** [update] Error 1 Here I'm stuck, knowing too little about Unix. Can anyone help me out? Thanks, Hakan