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Re: Verify Mail Has Valid 'From:' Field?

1998-01-13 07:45:58
Tue 98-01-13 era eriksson <era(_at_)iki(_dot_)fi> list.procmail
| 
| An alternative would be to use host(1), which does return a meaningful
| error code. (I believe it's shipped with BIND. It's not a standard
| program, though.)

host(1) seems to be fast when the host exists, but if it doesn't, as is 
the case in forged domains, ...yikes! 11 seconds per message. 

    % time host foo.bar.com   (not exist)
    --> 0.00u 0.03s 0:11.82 0.2%

    % time nslookup foo.bar.com
    --> 0.01u 0.03s 0:04.06 0.9%


    % time host geocities.com (does exist)
    0.00u 0.05s 0:00.08 62.5%

    % time nslookup geocities.com 
    --> 0.02u 0.03s 0:00.07 71.4%


jari