Anti-Spam SMTP Proxy "Anti-Spam SMTP Proxy" is a spam filter that sits on port 25 (smtp), and optionally also 465 (smtps) and 587 (submission), in front of your regular SMTP server.
ASSP relays the SMTP dialog between an incoming client and your SMTP server, intercepting the dialog as needed. ASSP performs a number of configurable spam checks and on detectinga spam message provides an immediate 5xx SMTP error code back to the client.
Non-spam messages are passed to the regular SMTP server for further processing and delivery. Spam messages can be blocked from delivery or subject-tagged and delivered.
ASSP offers: a whitelist of known good senders Bayesian checks on message headers and contents local user validation using RFC822 checks flat lists or LDAP lookup relay denial, HELO checking, SPF (Sender Policy Framework) checking, DNSBL (DNS Block List) checking using many block list services delaying of messages from unknown senders Virus detection.
Here are some key features of "Anti-Spam SMTP Proxy Server":
· Multiple Weighted DNSBLs
· Multiple URIBLs
· Weighted Regular Expression Filtering
· Penalty Box
· Attachment Blocking
· ClamAV and FileScan
· Blocking Reporting
· LDAP support
· Backscatter Detection
· Perl 5.8
What's New in This Release: [ read full changelog ]
· The mail analyzer leads some times in to a stuck Worker or MainThread, if the analyzed mail content is too
· long the analyze is now restricted to MaxBytes to prevent this.
· The regular expression optimization causes different content related problems.
· The structure of domain and user related regular expressions is internaly changed.
· Now the processing of the regular expressions takes much less time, because Perl needs no backtracking
· the memory usage is the same like before. It is save to use the Regex.Optimizer modules with this release!
· If the regex optimizer modules are used, it was possible that 'strong' optimized regular expressions
· (like localaddresses_flat) have lost there function, if the file size is very large.
· There is no known limit of the file size, where the regexes are still working well.
· For this reason, the 'strong' optimization is removed for all regular expressions and the 'simple'
· optimization is used instead.
· if 'removeDispositionNotification' was set to on, the r...