Not that I'm trying to discourage discussing sendmail issues on this
mailing list, but it seems to me that this is no way a NetBSD specific
problem, not to mention no way a mac68k specific problem.

So, I think you'd be better off taking your question to fj.mail (if
you want to talk about it in Japanese) or comp.mail.sendmail (if you
want to discuss it in English).  I mean you'd get better help at
other places than here.

BTW, I think this is not a name resolution issue, but a sendmail.cf
issue.  You need to modify your sendmail.cf.

ken