NAME¶
Mail::SpamAssassin::Plugin::AWL - Normalize scores via auto-whitelist
SYNOPSIS¶
To try this out, add this or uncomment this line in init.pre:
loadplugin Mail::SpamAssassin::Plugin::AWL
Use the supplied 60_awl.cf file (ie you don't have to do anything) or add these
lines to a .cf file:
header AWL eval:check_from_in_auto_whitelist()
describe AWL From: address is in the auto white-list
tflags AWL userconf noautolearn
priority AWL 1000
DESCRIPTION¶
This plugin module provides support for the auto-whitelist. It keeps track of
the average SpamAssassin score for senders. Senders are tracked using a
combination of their From: address and their IP address. It then uses that
average score to reduce the variability in scoring from message to message and
modifies the final score by pushing the result towards the historical average.
This improves the accuracy of filtering for most email.
This plugin module adds the following "tags" that can be used as
placeholders in certain options. See "Mail::SpamAssassin::Conf" for
more information on TEMPLATE TAGS.
_AWL_ AWL modifier
_AWLMEAN_ Mean score on which AWL modification is based
_AWLCOUNT_ Number of messages on which AWL modification is based
_AWLPRESCORE_ Score before AWL
USER PREFERENCES¶
The following options can be used in both site-wide ("local.cf") and
user-specific ("user_prefs") configuration files to customize how
SpamAssassin handles incoming email messages.
- use_auto_whitelist ( 0 | 1 ) (default: 1)
- Whether to use auto-whitelists. Auto-whitelists track the
long-term average score for each sender and then shift the score of new
messages toward that long-term average. This can increase or decrease the
score for messages, depending on the long-term behavior of the particular
correspondent.
For more information about the auto-whitelist system, please look at the the
"Automatic Whitelist System" section of the README file. The
auto-whitelist is not intended as a general-purpose replacement for static
whitelist entries added to your config files.
Note that certain tests are ignored when determining the final message
score:
- rules with tflags set to 'noautolearn'
- auto_whitelist_factor n (default: 0.5, range [0..1])
- How much towards the long-term mean for the sender to
regress a message. Basically, the algorithm is to track the long-term mean
score of messages for the sender ("mean"), and then once we have
otherwise fully calculated the score for this message ("score"),
we calculate the final score for the message as:
"finalscore" = "score" + ("mean" -
"score") * "factor"
So if "factor" = 0.5, then we'll move to half way between the
calculated score and the mean. If "factor" = 0.3, then we'll
move about 1/3 of the way from the score toward the mean.
"factor" = 1 means just use the long-term mean;
"factor" = 0 mean just use the calculated score.
- auto_whitelist_ipv4_mask_len n (default: 16, range
[0..32])
- The AWL database keeps only the specified number of
most-significant bits of an IPv4 address in its fields, so that different
individual IP addresses within a subnet belonging to the same owner are
managed under a single database record. As we have no information
available on the allocated address ranges of senders, this CIDR mask
length is only an approximation. The default is 16 bits, corresponding to
a former class B. Increase the number if a finer granularity is desired,
e.g. to 24 (class C) or 32. A value 0 is allowed but is not particularly
useful, as it would treat the whole internet as a single organization. The
number need not be a multiple of 8, any split is allowed.
- auto_whitelist_ipv6_mask_len n (default: 48, range
[0..128])
- The AWL database keeps only the specified number of
most-significant bits of an IPv6 address in its fields, so that different
individual IP addresses within a subnet belonging to the same owner are
managed under a single database record. As we have no information
available on the allocated address ranges of senders, this CIDR mask
length is only an approximation. The default is 48 bits, corresponding to
an address range commonly allocated to individual (smaller) organizations.
Increase the number for a finer granularity, e.g. to 64 or 96 or 128, or
decrease for wider ranges, e.g. 32. A value 0 is allowed but is not
particularly useful, as it would treat the whole internet as a single
organization. The number need not be a multiple of 4, any split is
allowed.
- user_awl_sql_override_username
- Used by the SQLBasedAddrList storage implementation.
If this option is set the SQLBasedAddrList module will override the set
username with the value given. This can be useful for implementing global
or group based auto-whitelist databases.
- auto_whitelist_distinguish_signed
- Used by the SQLBasedAddrList storage implementation.
If this option is set the SQLBasedAddrList module will keep separate
database entries for DKIM-validated e-mail addresses and for non-validated
ones. A pre-requisite when setting this option is that a field
awl.signedby exists in a SQL table, otherwise SQL operations will fail
(which is why we need this option at all - for compatibility with
pre-3.3.0 database schema). A plugin DKIM should also be enabled, as
otherwise there is no benefit from turning on this option.
ADMINISTRATOR SETTINGS¶
These settings differ from the ones above, in that they are considered 'more
privileged' -- even more than the ones in the
PRIVILEGED SETTINGS
section. No matter what "allow_user_rules" is set to, these can
never be set from a user's "user_prefs" file.
- auto_whitelist_factory module (default:
Mail::SpamAssassin::DBBasedAddrList)
- Select alternative whitelist factory module.
- auto_whitelist_path /path/filename (default:
~/.spamassassin/auto-whitelist)
- This is the automatic-whitelist directory and filename. By
default, each user has their own whitelist database in their
"~/.spamassassin" directory with mode 0700. For system-wide
SpamAssassin use, you may want to share this across all users, although
that is not recommended.
- auto_whitelist_db_modules Module ... (default: see
below)
- What database modules should be used for the auto-whitelist
storage database file. The first named module that can be loaded from the
perl include path will be used. The format is:
PreferredModuleName SecondBest ThirdBest ...
ie. a space-separated list of perl module names. The default is:
DB_File GDBM_File SDBM_File
NDBM_File is no longer supported, since it appears to have bugs that
preclude its use for the AWL (see SpamAssassin bug 4353).
- auto_whitelist_file_mode (default: 0700)
- The file mode bits used for the automatic-whitelist
directory or file.
Make sure you specify this using the 'x' mode bits set, as it may also be
used to create directories. However, if a file is created, the resulting
file will not have any execute bits set (the umask is set to 0111).
- user_awl_dsn
DBI:databasetype:databasename:hostname:port
- Used by the SQLBasedAddrList storage implementation.
This will set the DSN used to connect. Example:
"DBI:mysql:spamassassin:localhost"
- user_awl_sql_username username
- Used by the SQLBasedAddrList storage implementation.
The authorized username to connect to the above DSN.
- user_awl_sql_password password
- Used by the SQLBasedAddrList storage implementation.
The password for the database username, for the above DSN.
- user_awl_sql_table tablename
- Used by the SQLBasedAddrList storage implementation.
The table user auto-whitelists are stored in, for the above DSN.