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Relay e AntiSpam

Colaboração: Rubens Queiroz de Almeida

Data de Publicação: 06 de Abril de 2000

Para determinar se seu servidor de correio eletrônico pode ser vítima do ataque de espertalhões e ser usado para distribuir milhares de mensagens de spam, utilize os serviços oferecidos por mail-abuse.net.

Faça simplesmente uma conexão telnet para mail-abuse.net, e este computador fará então diversos testes para determinar a vulnerabilidade da configuração do seu servidor.

Transcrevo abaixo um teste que fiz em um servidor, que felizmente passou em todos os testes. O nome e o endereço IP do servidor foi mudado para proteger os inocentes. :)

  $ telnet mail-abuse.net
  Trying 204.152.184.74...
  Connected to mail-abuse.net.
  Escape character is '^]'.
  Connecting to 10.0.0.1 for anonymous test ...
  <<< 220 smtp.dominio.com.br ESMTP Sendmail 8.9.3/8.9.3; Fri, 31 Mar 2000 14:18:36 -0300 (EST)
  >>> HELO mail-abuse.org
  <<< 250 smtp.dominio.com.br Hello dante.mail-abuse.org [204.152.184.35], pleased to meet you
  Relay test 1
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<spamtest@mail-abuse.org>
  <<< 250 <spamtest@mail-abuse.org>... Sender ok
  >>> RCPT TO:<relaytest@mail-abuse.org>
  <<< 550 <relaytest@mail-abuse.org>... Relaying denied
  Relay test 2
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<spamtest>
  <<< 553 <spamtest>... Domain name required
  Relay test 3
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<>
  <<< 250 <>... Sender ok
  >>> RCPT TO:<relaytest@mail-abuse.org>
  <<< 550 <relaytest@mail-abuse.org>... Relaying denied
  Relay test 4
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<spamtest@smtp.dominio.com.br>
  <<< 250 <spamtest@smtp.dominio.com.br>... Sender ok
  >>> RCPT TO:<relaytest@mail-abuse.org>
  <<< 550 <relaytest@mail-abuse.org>... Relaying denied
  Relay test 5
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<spamtest@[10.0.0.1]>
  <<< 250 <spamtest@[10.0.0.1]>... Sender ok
  >>> RCPT TO:<relaytest@mail-abuse.org>
  <<< 550 <relaytest@mail-abuse.org>... Relaying denied
  Relay test 6
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<spamtest@smtp.dominio.com.br>
  <<< 250 <spamtest@smtp.dominio.com.br>... Sender ok
  >>> RCPT TO:<relaytest%mail-abuse.org@smtp.dominio.com.br>
  <<< 550 <relaytest%mail-abuse.org@smtp.dominio.com.br>... Relaying denied
  Relay test 7
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<spamtest@smtp.dominio.com.br>
  <<< 250 <spamtest@smtp.dominio.com.br>... Sender ok
  >>> RCPT TO:<relaytest%mail-abuse.org@smtp.dominio.com.br>
  <<< 550 <relaytest%mail-abuse.org@smtp.dominio.com.br>... Relaying denied
  Relay test 8
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<spamtest@smtp.dominio.com.br>
  <<< 250 <spamtest@smtp.dominio.com.br>... Sender ok
  >>> RCPT TO:<"relaytest@mail-abuse.org">
  <<< 550 <"relaytest@mail-abuse.org">... Relaying denied
  Relay test 9
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<spamtest@smtp.dominio.com.br>
  <<< 250 <spamtest@smtp.dominio.com.br>... Sender ok
  >>> RCPT TO:<"relaytest%mail-abuse.org">
  <<< 550 <"relaytest%mail-abuse.org">... Relaying denied
  Relay test 10
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<spamtest@smtp.dominio.com.br>
  <<< 250 <spamtest@smtp.dominio.com.br>... Sender ok
  >>> RCPT TO:<relaytest@mail-abuse.org@smtp.dominio.com.br>
  <<< 550 <relaytest@mail-abuse.org@smtp.dominio.com.br>... Relaying denied
  Relay test 11
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<spamtest@smtp.dominio.com.br>
  <<< 250 <spamtest@smtp.dominio.com.br>... Sender ok
  >>> RCPT TO:<"relaytest@mail-abuse.org"@smtp.dominio.com.br>
  <<< 550 <"relaytest@mail-abuse.org"@smtp.dominio.com.br>... Relaying denied
  Relay test 12
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<spamtest@smtp.dominio.com.br>
  <<< 250 <spamtest@smtp.dominio.com.br>... Sender ok
  >>> RCPT TO:<relaytest@mail-abuse.org@smtp.dominio.com.br>
  <<< 550 <relaytest@mail-abuse.org@smtp.dominio.com.br>... Relaying denied
  Relay test 13
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<spamtest@smtp.dominio.com.br>
  <<< 250 <spamtest@smtp.dominio.com.br>... Sender ok
  >>> RCPT TO:<@smtp.dominio.com.br:relaytest@mail-abuse.org>
  <<< 550 <@smtp.dominio.com.br:relaytest@mail-abuse.org>... Relaying denied
  Relay test 14
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<spamtest@smtp.dominio.com.br>
  <<< 250 <spamtest@smtp.dominio.com.br>... Sender ok
  >>> RCPT TO:<@smtp.dominio.com.br:relaytest@mail-abuse.org>
  <<< 550 <@smtp.dominio.com.br:relaytest@mail-abuse.org>... Relaying denied
  Relay test 15
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<spamtest@>
  <<< 553 <spamtest@>... Domain name required
  Relay test 16
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<spamtest@smtp.dominio.com.br>
  <<< 250 <spamtest@smtp.dominio.com.br>... Sender ok
  >>> RCPT TO:<mail-abuse.org!relaytest>
  <<< 550 <mail-abuse.org!relaytest>... User unknown
  Relay test 17
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<spamtest@smtp.dominio.com.br>
  <<< 250 <spamtest@smtp.dominio.com.br>... Sender ok
  >>> RCPT TO:<mail-abuse.org!relaytest@smtp.dominio.com.br>
  <<< 550 <mail-abuse.org!relaytest@smtp.dominio.com.br>... User unknown
  Relay test 18
  >>> RSET
  <<< 250 Reset state
  >>> MAIL FROM:<spamtest@smtp.dominio.com.br>
  <<< 250 <spamtest@smtp.dominio.com.br>... Sender ok
  >>> RCPT TO:<mail-abuse.org!relaytest@smtp.dominio.com.br>
  <<< 550 <mail-abuse.org!relaytest@smtp.dominio.com.br>... User unknown
  Relay test result
  All tests performed, no relays accepted.