SCO-5.0.7 Setup Email-2.5.1 problem

Did anyone got Email-2.5.1 working on Sco 5? It goes thru
./configure
with no problem
but bump into an error message when use
make

I am including the error message bellow:

Undefined first referenced
symbol in file
__abbr_table_1.1 email.o
stat64 file_io.o
__xassert addr_parse.o
_xgetlogin_r email.o
_xmknod execgpg.o
_xttyname_r email.o
creat64 message.o
fopen64 email.o
fstat64 progress_bar.o
_nuname conf.o
UX:i386ld: ERROR: Symbol referencing errors. No output written to email
*** Error code 1 (bu21)
*** Error code 1 (bu21)