[Mimedefang] preferred pthread library

[John Nemeth]

     Is there a preferred pthread library to use when the OS doesn't
have a native one?  I tried GNU PTH 2.0.0 and the slaves crashed when
sendmail tried to connect.  I then tried "unproven-pthreads" and the
multiplexor simply ended up killing the slaves because they were busy
when sendmail tried to connect.  Right now I'm trying to get MD to
compile with MIT pthreads, then I plan on trying PTL2.  Does anybody
have any other suggestions?