[Exim] Partially functioning .forward pipe

When I try to pipe procmail, it only works if I email myself!

I'm trying to use SpamAssassin to filter my mail, so I have the .forward file below:

"| /usr/bin/procmail -f-"

and I have put a symbolic link to procmail in /etc/smrsh/procmail:

lrwxrwxrwx    1 root     root           17 Dec 19  2002 procmail -> /usr/bin/procmail

and I have a default .procmailrc file from SpamAssassin. Everything seems to work
fine when I email myself using >mail halej but when I send a message through netscape
or get someone else to mail me the pipe fails:

  pipe to | /usr/bin/procmail -f-
    generated by halej@???
    Child process of address_pipe transport returned 69 (could mean service or program unavailable) from command:
    /usr/bin/procmail

Any suggestions would be very much appreciated!

Thanks,

Josh.