Filtragem de Email com Red Hat Linux

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Filtragem de Email com Red Hat
Linux Implementações Práticas e Apresentação de
Laboratórios
Ruben Oliveira RHCE RHCX MCSE MCITP
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• Postfix Mail Server / GW Filter
• Mailscanner
• SpamAssassin
• Mailwatch
• Webmin/Usermin
• Dovecot
• Apresentação de Laboratórios

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• Postfix Mail Server / GW Filter

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• Postfix Mail Server / GW Filter

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• Postfix
• main.cf
• multiple domain
• mail relaying
• sasl / tls

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• MailScanner
• www.mailscanner.info
• A Free Anti-Virus and Anti-Spam Filter
• Protecting over 1 billion e-mails every day
• Over 1 million downloads
• Perl based
• Instalação simples
• Compatível com Sendmail/Postfix/Exim,etc
• como alternativas amavisd-new

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• Spam Scanning
• Most of the spam scanning is done with the help
  of SpamAssassin
• DNS blacklists
• over 850 heuristic rules
• Bayesian probability system
• Distributed network-based checks such as
• Razor, DCC, Pyzor which track the frequency of
  messages around the world to identify spam

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• Virus Scanning
• Scans all e-mail passing through it for viruses
  using any combination of the supported anti-virus
  engines
• Many sites run 2 or 3 different engines for
  better coverage and resistance against brand new
  viruses
• Anti-Virus Engines 20 are supported, including
  all the major market leaders
• ClamAV is free and has greatly improved over the
  past year

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• Virus Handling
• Attachments containing viruses or other security
  problems are removed
• All safe content is delivered untouched
• Recipients and senders may get a warning
  explaining what happened and who they should
  contact for help
• System admin notified of basic details of message
  and what viruses were found

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• Attachment Filenames
• Allows/denies attachments based on filename and
  file content, providing implementation of any
  email security policy.
• Easily used to block attachments which are
  common ways of disguising viruses,
  e.g. ReadMe.doc.exe
• These can be varied for different users.

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• Highly Configurable
• Virtually all configuration parameters can be
  set using fixed values, rulesets or Custom
  Functions
• Rulesets allow different values for any users or
  domains you specify
• Reports are supplied in 15 languages
• Language can be different for different domains
  and users

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• Rulesets
• Archive Mail /etc/MailScanner/rules/arch.rules
  -)?
• From joao_at_dominio.pt joana_at_dominio2.pt
• From - Matches when the message is from a
  matching address
• To - Matches when the message is to a
  matching address
• FromOrTo - Matches when the message is from or
  to a matching address
• user_at_sub.domain.com Individual address
• _at_domain.com Any user at 1 specific
  domain
• 192.168.21.0/24 Any SMTP client IP
  address in this network
• _at_ Default value
• default Default value
• Destination email address / directorio com ou sem
  datas appended / ficheiro mbox

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• Custom Functions
• These allow implementation of any
  other configuration model you choose, including
  external databases of user options
• Many useful examples are provided
• Minimal Perl knowledge needed

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• Hash-Sharing Systems
• Send a checksum of a message to an online
  database of spam.
• "Has anyone reported this as spam?". The online
  database can report back "yes", allowing your
  mail system to raise the spam score for that
  message.
• Pyzor Razor DCC

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• Mailwatch
• MailWatch for MailScanner is a web-based
  front-end to MailScanner written in PHP, MySQL
• Load Average and Todays Totals for Messages,
  Spam, Viruses and Blocked Content.
• Colour-coded display of recently processed mail.
• Drill-down onto each message to see detailed
  information.
• Quarantine management allows you to release,
  delete or run sa-learn across any quarantined
  messages.
• Reports with customisable filters and graphs

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• Webmin / Usermin
• Gestão e Utilização do servidor via https

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• Dovecot
• Dovecot is an open source IMAP and POP3 server
  for Linux
• security primarily in mind.
• It's fast, simple to set up, requires no special
  administration and it uses very little memory.

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• Laboratórios
• Utilização de Máquinas Virtuais
• Instalação de um servidor de email com filtragem
  de spam e virus, além de webmail e gestão via
  http

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Obrigado Perguntas e Respostas ruben.oliveira_at_r
umos.pt