Sieve Pipe plugin for Pigeonhole Introduction ------------ Sieve (RFC 5228) is a highly extensible machine language specifically tailored for internet message filtering. For the Dovecot Secure IMAP server, Sieve support is provided by the Pigeonhole Sieve plugin. This package provides a plugin for Pigeonhole called "sieve_pipe", which extends the Sieve filtering implementation with an action command for piping messages to a pre-defined set of external progams. The Sieve language is explicitly designed to be powerful enough to be useful yet limited in order to allow for a safe server-side filtering system. Therefore, the base specification of the language makes it impossible for users to do anything more complex (and dangerous) than write simple mail filters. One of the consequences of this security-minded design is that users cannot execute external programs from their mail filter. Particularly for server-side filtering setups in which mail accounts have no corresponding system account, allowing the execution of arbitrary programs from the mail filter can be a significant security risk. However, such functionality can also be very useful, for instance to easily implement a custom action or external effect that Sieve normally cannot provide. The "sieve_pipe" plugin provides an extension to the Sieve filtering language adding a new action command for piping messages to a pre-defined set of external programs. To mitigate the security concerns, the external programs cannot be chosen arbitrarily; the available programs are restricted through administrator configuration. This extension is specific to the Pigeonhole Sieve implementation for the Dovecot Secure IMAP server. It will therefore most likely not be supported by web interfaces or GUI-based Sieve editors. This extension is primarily meant for use in small setups or global scripts that are managed by the systems administrator. Compiling and Configuring ------------------------- Refer to INSTALL file. Using ----- Refer to doc/rfc/spec-bosch-sieve-pipe.txt for a specification of the Sieve language extension. Implementation Status --------------------- The "vnd.dovecot.pipe" Sieve language extension introduced by this plugin is vendor-specific with draft status and its implementation for Pigeonhole is experimental, which means that the language extension is still subject to change and that the current implementation is not thoroughly tested. Authors ------- Refer to AUTHORS file. Contact Info ------------ Stephan Bosch IRC: Freenode, #dovecot, S[r]us Web: http://pigeonhole.dovecot.org Please use the Dovecot mailing list for questions about this plugin. You can post to the list without subscribing, the mail then waits in a moderator queue for a while. See http://dovecot.org/mailinglists.html