smtp-vilter is a high performance content filter for sendmail to detect e-mail viruses and spam. smtp-vilter decides whether to pass, discard or simply mark an e-mail message based on the results of a content scan and user defined strategies. It can interact with the pf packet filter when it detects spam, viruses or unwanted content by adding the IP address of the sending host to a PF table. smtp-vilter does not do the scanning by itself, it relies on third-party products like ClamAV, SpamAssassin, or any ICAP capable scanner for this purpose. smtp-vilter uses the milter API to communicate with sendmail and one or more backends to communicate with the actual virus or spam scanning engines. The backends can be chained to perform a series of checks on one message in one run. The software is highly configurable and provides mechanisms for secure operation. The backends included in the distribution provide support for the Clam AntiVirus Daemon (clamd), the Spamassassins Daemon (spamd), ICAP capable backends (icap), and the standalone attachment backend to filter out unwanted attachments. The backends are realised as shared libraries that are loaded dynamically when smtp-vilter starts. All backends have their own configuration file. smtp-vilter is documented in the following manpages: smtp-vilter(8) Running the smtp-vilter smtp-vilter.conf(5) The smtp-vilter config file