SpamAssassin
SpamAssassin is a powerful tool to help solve the
Spam Problem. The Makers of SpamAssassin explain how their
product works:
(SpamAssassin) Us(es) its rule base, (and) a wide range of heuristic tests on mail headers and body text to identify
"spam", also known as unsolicited commercial e-mail.
spamassassin.apache.org
The flexibility of SpamAssassin combines with its excellent design to make it an easy way to help you take
control of your E-mail accounts and stop spam from wasting your time and resources.
Installation and Configuration
We have an easy-to-use installation and configuration tool to help you get SpamAssassin running and configured
on your Virtual Private Server. To install or configure SpamAssassin,
SSH or Telnet to your Virtual Private Server and run the
following command.
% vinstall spamassassin
SpamAssassin applies a number of tests to an incoming message, and each test returns a score. If enough tests
return a combined score that is high enough (the default is 5), SpamAssassin can tag the message as being
spam. Once a message has been tagged, there are a number of possible actions that can be taken with the
message. Both tagging and actions can be handled either as a system-wide or as a user specific filter.
- System-wide Filters - This applies SpamAssassin tests to
every E-mail message that arrives on your Virtual Private Server, regardless of the intended recipient.
While scanning every incoming message for spam characteristics is a good idea, you may want to have the
system settings simply tag messages and deliver them normally. This avoids accidentally losing the
occasional legitimate message that has spam-like characteristics.
-
User Specific Filters - For individual users, different methods
of dealing with spam may be preferred. The user specific settings allow you to set up specific users with
different ways of dealing with messages tagged as spam.
Once a message has been tagged, SpamAssassin will do one of the following with the message, depending on your
system and user settings.
- Deliver Tagged messages along with Untagged messages normally. This allows the user to easily see if a
message is tagged as spam, but allows them to make the final decision to read the message or not. If you
have system-wide filtering on, it is a good idea to use this option for the system-level filtering.
- Deliver Spam to a special mailbox. Untagged messages will be delivered as usual, but tagged messages
will be delivered to a special mailbox (or IMAP folder). This is a good user level setting for IMAP users who
don't want potential spam cluttering their INBOX, but want to have the option to check through to see if
there's anything important among the tagged messages.
- Deliver spam to a special mailbox and forward non-spam to another address. If a user has another account
that they forward their messages to, this allows you to filter out spam before forwarding the messages to
their account
- Forward Spam to another address. By doing this, non-spam is delivered normally, but spam can be forwarded
to an account on a different server.
- Delete Spam. This is not a recommended option, since some spam may in fact be legitimate. However, you
can select to have all messages tagged as spam deleted, either on a system level, or just for specific users.
- Delete Spam and forward non-spam to another address. Again, this is not recommended, but you can have all
the tagged messages deleted before forwarding un-tagged messages to a remote E-mail account.
SpamAssassin can be configured to keep a log of its activity. Logs can be useful in tracking down problems and
errors, but like any other log file, your SpamAssassin logs will need to be cleared out occasionally to prevent
them from using up all your disk space. You can use cron to
archive or empty your spam log files.
The vinstall module for SpamAssassin only configures the most basic settings required to get SpamAssassin
working on your Virtual Private Server. SpamAssassin has a number of additional configuration options which can be
set by editing specific configuration files. For more information on additional configuration options, see the
documentation.
spamd
The spamd can be a more efficient way of running SpamAssassin on the VPS. Enabling spamd requires a few
modifications and customizations to work:
Patching spamd on the VPS
Removing SpamAssassin
If you want to remove SpamAssassin filters, either for the full system or for specific users, you can use the
following command.
% vuninstall spamassassin
After running the command, you will be given the option to delete system filters (but keep user filters), delete
a specific user's filters, or to remove all SpamAssassin filters and the SpamAssassin program files from your
Virtual Private Server.
Documentation
There are a number of sources of documentation for SpamAssassin. You can access the man pages using the
following commands.
% man spamassassin
% man Mail::SpamAssassin::Conf
More Information
Information about the SpamAssassin filtering engine can be found at:
http://spamassassin.apache.org/
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