Filtragem Email
Filtragem de Email
com Red Hat Linux
Implementações Práticas e
Apresentação de Laboratórios
Ruben Oliveira
RHCE RHCX MCSE MCITP
Filtragem Email
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Postfix Mail Server / GW Filter
Mailscanner
SpamAssassin
Mailwatch
Webmin/Usermin
Dovecot
Apresentação de Laboratórios
Filtragem Email
• Postfix Mail Server / GW Filter
Filtragem Email
• Postfix Mail Server / GW Filter
Filtragem Email
• Postfix
• main.cf
• multiple domain
• mail relaying
•sasl / tls
Filtragem Email
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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
Filtragem Email
• 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
Filtragem Email
• Virus Scanning
• Scans all e-mail passing through it for viruses
using any combination of the supported antivirus 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
Filtragem Email
• 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
Filtragem Email
• 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.
Filtragem Email
• 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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Filtragem Email
• Rulesets
• Archive Mail = /etc/MailScanner/rules/arch.rules
• From: [email protected] [email protected]
;-)
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From:
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To:
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FromOrTo: - Matches when the message is from or to a matching address
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[email protected]
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*@domain.com
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192.168.21.0/24
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*@*
# Default value
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default
# Default value
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Destination email address / directorio com ou sem datas appended / ficheiro mbox
- Matches when the message is from a matching address
- Matches when the message is to a matching address
# Individual address
# Any user at 1 specific domain
# Any SMTP client IP address in this network
Filtragem Email
• 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
Filtragem Email
• 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
Filtragem Email
• Mailwatch
• MailWatch for MailScanner is a web-based frontend to MailScanner written in PHP, MySQL
• Load Average and Today’s 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
Filtragem Email
Filtragem Email
Filtragem Email
Webmin / Usermin
• Gestão e Utilização do servidor via https
Filtragem Email
• 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.
Filtragem Email
• Laboratórios
• Utilização de Máquinas Virtuais
• Instalação de um servidor de email com
filtragem de spam e virus, além de webmail e
gestão via http
Filtragem Email
Obrigado
Perguntas e Respostas
[email protected]