NAME

       rlytest - test mail host for third-party relay

SYNOPSIS

       rlytest [-f sender_addr] [-u recip_addr] [-c comment] [-t
       timeout] target_host

DESCRIPTION

       The rlytest utility performs a test on target_host to
       determine whether it will relay third-party email.  It
       will try to relay an email message to yourself through
       that host.  A host that allows third-party relay is
       subject to attack by Internet vandals, and frequently is
       hijacked by spammers to relay massive amounts of junk
       email.  A host that allows third-party relay should be
       immediately secured, disconnected, or shunned as a menace
       to the Internet.

       The following options are available:

       -f sender_addr
           Specifies the (MAIL FROM) email address to use on the
           probe.  By default, rlytest tries to calculate an
           email address in the target domain.  This is to ensure
           that the host is not using simple (and easily
           defeated) envelope checks for anti-relay protection.

       -u recip_addr
           Specifies the (RCPT TO) email address to use on the
           probe.  By default, rlytest tries to calculate your
           email address and use that.  A host that is
           susceptible to relay will deliver a probe message to
           this address.

       -c comment
           Embed comment in the body of the test message.  This
           may be useful, for instance, if you are doing some
           automatic testing and want to insert cookies into the
           messages.

       -t timeout
           Sets the timeout value (default is 60 seconds) for
           certain operations.

       If the message was accepted, the program will terminate
       with a zero exit status and display a message to stderr
       similar to:

         rlytest: relay accepted - status code 221

       If the remote host refused to relay the message, the
       program will terminate with a zero exit status dislay a
       message to stderr similar to:

         rlytest: relay rejected - status code 571

       A non-zero exit status indicates a program error, such as
       a bad hostname or host not resopnding.

EXAMPLE

       Here is an example, showing a host that refuses third-
       party relay:

         $ ./rlytest mail.example.dom
         Connecting to mail.example.dom ...
         <<< 220 mail.example.dom ready
         >>> HELO garcon.unicom.com
         <<< 250 Hello garcon.unicom.com, pleased to meet you
         >>> MAIL FROM:<[email protected]>
         <<< 250 <[email protected]>... Sender ok
         >>> RCPT TO:<[email protected]>
         <<< 550 <[email protected]>... Relaying Denied
         rlytest: relay rejected - status code 550

BUGS

       There is no reliable and portable method to determine the
       local host's fully qualified domain name.  If the utility
       bombs out complaining about FQDN problems, read the "host
       name configuration" information near the top of the
       script.

SEE ALSO

       mail(1), sendmail(8), smtpd(8)

AUTHOR

         Chip Rosenthal
         Unicom Systems Development
         <[email protected]>

         $Id: rlytest,v 1.17 1999/08/20 07:11:54 chip Exp $
         See http://www.unicom.com/sw/#rlytest for latest version.