manitou-mdx plugins

The functionalities of manitou-mdx can be extended or customized by writing Perl modules called plugins, whose structure is described in the Plugins Reference page.

Some examples of what plugins can do:

• automatically classify a message.
• call external filters such as anti-virus and anti-spam and act upon the result.
• match the sender with another database (customer db, whitelist, blacklist,...)
• route a message, change its priority.
• add additional information in headers or the private note.
• analyze and modify attachments and/or body.

• incoming_preprocess_plugins are called before a message is opened and analyzed by manitou-mdx, and have read and write access to the raw mail file. For example, a sample spamassassin client is implemented as an incoming_preprocess_plugins, because SA expects a raw mail file, as does clamav.
  
  
• incoming_mimeprocess_plugins are called after the message has been parsed by manitou-mdx, and before it's put into the database. These plugins have read/write access to the parsed form of the message (perl MIME object with decoded parts).
  
  
• incoming_postprocess_plugins are called after a message has been commited into the database and all associated actions have been carried out.
  
  
• outgoing_plugins are called before passing an outgoing message to the mail system. They can modify the message, for example by adding a digital signature or additional headers.
  
  
• maintenance_plugins can be called periodically by the mdx to carry out special maintenance tasks such as cleaning up tables, reclaiming database space, running statistics, issuing alerts... Maintenance plugins play the kind of role that could be assigned to crontab scripts, except that:
  - they have access to an already opened database connection, and current configuration options.
  - they're not run concurrently with the other mdx functions, such as importing or sending messages, so that no database access contention is created.
  
  

The distribution archive include those sample plugins, in the scripts/plugins directory:

• spamc: a pre-process plugin that calls the SpamAssassin client (spamc) on incoming messages to determine their spam probability and add a user-defined tag when positive.
  
  
• mswordindexer: a mime-process plugin that pass MS-word .doc attachments on to wvWare, convert them to Unicode text and add their words to the full-text index of the body. This allows the user interface's search engine to retrieve those messages based on the contents of their attachments.
  
  
• undouble_newlines: a pre-process plugin that checks and fixes mailfiles in which all end of lines are doubled, resulting in an incorrect MIME structure. Apparently, some pop3 servers may deliver mail this way, so activating this plugin allows to overcome this annoying feature.
  
  
• bayes_classify: a mime-process plugin that does automatic mail classification according to words contained in the message. The so-called "naive bayesian algorithm" has recently become popular for its efficiency in spam filtering, but can also be used more generally for automated classification: a Wikipedia entry explains this in detail.
  Read the case study on automatic language detection for a step by step introduction on how to set up and use the classifier plugin in Manitou-Mail.
  
  
• attach_uploader: an outgoing plugin that replaces large attachments by a web link to the contents before sending a message. Such attachments are not welcome in Internet mail, and sometimes rejected, because they bog down mail servers, eat people's mailboxes quotas, and may cause trouble when being fetched. When this plugin is enabled, large attachments (the inline maximum size is configurable) are uploaded to an FTP server instead of being sent along with the mail.
  The plugin let Manitou-Mail users just attach files as usual and let manitou-mdx care whether they should be part of the message or taken outside.
  
  

[common]
plugins_directory = /usr/local/manitou/plugins
# vacuum every 2 hours
maintenance_plugins = 2h vacuum

[mailbox@company.com]
# these plugins will be called only for that mailbox
incoming_preprocess_plugins = spamc("tag for spam")
outgoing_plugins = gpgsign
incoming_postprocess_plugins = guesslang("en","fr") \
                               anotherplugin(arg1,arg2,...)