Filter

Description

Whitelist

The whitelist includes email addresses from which all emails are accepted, regardless of their content. None of MailWasher Server's junk mail filters are applied to messages from addresses on the whitelist, therefore care must be taken when adding addresses. It is possible to avoid false negatives by ensuring that you do not add entire domain names to your whitelist, for example, *@aol.com.

For more information about how to use the whitelist, see whitelist overview.

Blacklist

MailWasher Server filters all messages from addresses that appear on the Address blacklist. All users are affected by the Address blacklist, therefore it is recommended that entire domains are not added to the blacklist as this prevents all end users from receiving possible legitimate messages from any address at that domain.

For more information about how to use the Address blacklist, see Address blacklist overview.

IP-based RBLs

Real-time blackhole lists (RBLs) are used to list the servers and domains of organisations that have been identified as senders of junk emails. IP-based RBLs (ip4r RBLs) are lists of IP addresses of servers that have been identified as sending or relaying junk mail. Firetrust recommends that you carefully investigate each RBL service for accuracy, before you begin using them. Inaccurate RBLs can result in a high false positive rate.

For more information about how to use RBLs, see Real-time blackhole list services overview.

Domain-based RBLs

Domain-based real-time blackhole lists (rhsbl RBLs) are lists of domain names from the return-path address on received junk email messages. False positives are possible if an RBL lists a domain that spammers have been spoofing messages from. Spammers often spoof the email address that they send from, which can result in these domains being erroneously added to a domain-based RBLs blacklist.

For more information about how to use RBLs, see Real-time blackhole list services overview.

FirstAlert!

FirstAlert! is a database of reported and known junk mail messages that is used to eliminate future circulation of junk mail. Both FirstAlert! users and administrators verify the junk mail, therefore ensuring a high rate of accuracy before messages are added to the database.

For more information about how to use FirstAlert!, see FirstAlert! overview.

Statistical content analysis

MailWasher Server's statistical content analysis is similar to Bayesian filtering, but has the addition of using advanced trait based analysis as well as traditional word based analysis. Junk messages that match statistical content filters are always rejected without notification by MailWasher Server, however these messages display as quarantined. False positives may occur during the initial phase of training the filter, but this can be limited by modifying the sensitivity of the filter.

For more information about how to use statistical content analysis filters, see Statistical Content Analysis Overview