Download Anti-Spam SMTP Proxy Server

Sebuah software berlisensi Open Source yang cukup mantap dan to-the-point. Beberapa teknologi anti spam sudah berulang kali dicoba namun sepertinya teknologi lain baik itu berbayar maupun berlisensi Open Source yang dicoba masih menggunakan konsep lama, yaitu content base dan sender reputation. Mengapa teknologi tersebut tidak bisa di rasa cocok ? Karena secara sederhana, spam juga dapat mudah dibasmi dengan 3 metode sederhana (ini dikutip dari website ASSP):

  • Most spam has an invalid bounce address, so notifying non-delivery simply bounces to Postmaster, creating even more wasted bandwidth. Failing to notify non-delivery is a problem for false-positives. The SMTP server is the only place where spam can be stopped before entering your system.
  • The only possible feedback for spammers to void an address is from the SMTP server.
  • Spam that passes through your SMTP server into mailboxes incurs cost to your organization: storage, transmission, backup, deletion — in all these ways spam costs you money. The only way to minimize cost is to reject it at the initial point.

Bagaimanapun juga, teknologi MTA (sistem mail exchange) terlalu lambat untuk bisa beradopsi dengan teknologi baru spam, dimana pada spammer terkenal sangat agresif & cepat dalam melakukan adaptasi teknologi MTA. Akibatnya kebanyakan SMTP server kurang cepat dipersenjatai alat-alat penghalau spam.

Mengadopsi kelemahan dunia MTA dalam menyusul teknologi spam, maka jalan tengahnya adalah digunakan sebuah SMTP proxy yang listen at port 25 dan meneruskan ke MTA (yang bodoh) sebagai mail queue saja, dengan demikian SMTP server diimplementasi dalam arsitektur sistem sebagai sistem pada second layer.

Baca Juga : Download Shadowsocks for Windows A secure socks5 proxy for Windows

Features

  • Multiple Weighted DNSBLs
  • Multiple Weighted URIBLs
  • Greylisting
  • Weighted Regular Expression Filtering
  • Bayesian
  • Penalty Box
  • SenderBase
  • SSL/TLS
  • SPF/SRS
  • Attachment Blocking
  • ClamAV and FileScan
  • Blocking Reporting
  • LDAP support
  • Backscatter Detection
  • recipient replacement / GUI user access rights management
  • MIME charset conversion / DKIM check and signing
  • multi DB support for all hashes / level based open plugin support
  • transparent TCP proxy support
  • Plugins: archive, full attachment check and replacement, OCR
  • damping (steal spammers time)
  • AUTH to relay host / POP3 collector
  • configuration value and file synchronization
  • Block Reports design could be customized
  • Razor2 and DCC support using Plugin
  • SNMP support (monitoring, configuring, controll-API)
  • user group import (file or LDAP or command based)
  • automatic crash analyzer Hidden Markov Model
  • IPv6 socket support
  • word stemming (several languages) for Bayesian analyzer
  • Perl module autoupdate via PPM or CPAN
  • Hidden Markov Model spam detection engine
  • full unicode support
  • DMARC support
  • privat Whitelist (legacy, domain based, user based)
  • privat IP and Domain lists (legacy, domain based, user based)
  • CPU affinity settings
  • web file commander
  • graphical statistic output (SVG)
  • native SSL support for target hosts
  • client SSL-certificate validation
  • privat SMIME signing
  • corporate SMIME signing, using a single privat certificate
  • content based executable attachment blocking
  • content based compressed attachment blocking
  • BATV check and signing
  • Message-ID signing and check FBMTV
  • remote support
  • Authenticated Received Chain (ARC) processing and signing
  • RSS feeds for blocked emails using Plugin
  • zero day virus detection
  • VirusTotal API

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