Advanced notes

Documentation for advanced usage

Mail::SpamAssassin::Conf: Complete documentation on user preferences which can be edited under the Rules tab.
Tests: Complete list of tests which SpamAssassin performs on mail messages to determine if they are spam or not.
Command-line options: Technical details on SAproxy underlying Perl script (pop3proxy.pl), which include the command-line options for saproxy.exe.

File locations

The first time you run SAproxy, it will create a subfolder .spamassassin in your UserProfile folder (typically C:\Documents and Settings\User). This is where user_prefs and hostmap.txt are located. You can customize these files via the GUI interface (see Configuring SAproxy) by editing the content of Rules and Host Map tabs, respectively. This folder is also a default location for the log file. You can enable debugging by running SAproxy with --debug switch.

System-wide options are stored in the etc\spamassassin subfolder of the folder, where SAproxy is installed, typically C:\Program Files\SAproxy\etc\spamassassin. You can edit local.cf there, but make sure to read documentation first. One of the most useful settings there is the parameter that lists “trusted” networks, which should merely include your own ISP so that its mail servers will not be unnecessarily checked against the online blacklists.

Known problems (not bugs)

Nonlocal network tests are enabled by default, which slightly delays processing of incoming mail. You can edit the settings in Rules, disable network tests system-wide in the Settings, or run SAproxy with --local switch.

When people send you email from ISPs which allow spammers on their network or do not bother to configure their servers properly, there is a good chance that their messages will test positive for spam. In this case you can either put them into the whitelist (in Rules) or disable some online tests.

Supported protocols

SAproxy supports most of the POP3 protocol as per RFCs 1939 (POP3 protocol) and 2449 (Extensions to POP3). Since marking up a message in transit between the POP3 server and the mail client can "break" the protocol, there are a variety of options to help your client deal with this. SAproxy was tested with a number of popular Win32 mail clients, which were found to be pretty good at dealing with the protocol being "broken" in this way, but your mileage may vary.

Notably, SAproxy does not support RFC 2222, Simple Authentication and Security Layer (SASL), nor RFC 1734, POP3 AUTHentication command. By default, the optional POP3 TOP command is not supported, but you can override this (see the --allowtop option (which is not exposed in the GUI). SASL and TOP are also removed from the results of an RFC 2449 CAPA command as well. RFC 2449 Pipelining is supported.

SpamAssassin is a very full featured mail analysis package, but due to the constraints of the Win32 platform and the nature of being a network proxy, SAproxy does not provide some of the extended SpamAssassin tests, specifically Razor and DCC. Auto-whitelisting and DNS tests are supported, but From: address reverse-lookups are turned off to avoid long timeouts.

SAproxy also does not report any detected spam. If you want to complain about spam, that's up to you, we just try to spot it.

RFCs

RFC 1939, POP3 Protocol
RFC 2449, POP3 Extension Mechanism
RFC 1734, POP3 AUTHentication command
RFC 2222, Simple Authentication and Security Layer
RFC 3206, The SYS and AUTH POP Response Codes