Complete Contents
Chapter 1 Getting Started With Netscape Messaging Server
Chapter 2 Configuring IMAP and POP Services
Chapter 3 Configuring SMTP Services
Chapter 4 Managing Mail Users and Mailing Lists
Chapter 5 Managing the Message Store
Chapter 6 Security and Access Control
Chapter 7 Working With SMTP Plugins
Chapter 8 Filtering Unsolicited Bulk Email
Chapter 9 Message Routing
Chapter 10 Monitoring and Maintaining Your Server
Chapter 11 Logging and Log Analysis
Appendix A Command Line Utilities
Appendix B Program Delivery
Appendix C sendmail Migration and Compatibility
Appendix D SNMP MIB
Glossary
Messaging Server Administrator's Guide: Working With SMTP Plug-Ins
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Chapter 7 Working With SMTP Plug-Ins

This chapter describes how to install and configure SMTP plug-ins, dynamic libraries that extend the capabilities of Messaging Server. For instructions on how to develop SMTP plug-ins, and for a detailed description of the plug-in programming interface, see Messaging Server Plug-In API Guide.

For information on using the specific SMTP plug-in that allows you to filter unsolicited bulk email (UBE), see Chapter 8, Filtering Unsolicited Bulk Email.

This chapter contains the following sections:
About SMTP Plug-Ins
Netscape Messaging Server 4.0 provides an application programming interface (API) that allows third parties to create server plug-ins that can add site-specific functionality to Messaging Server. Developers use the Messaging Server Plug-in API to

Message-processing plugins can include character-set converters or content filters that implement site-specific firewall functionality, filtering out suspicious incoming or outgoing attachments. Message-splitting plug-ins can be used to customize the message content for a subset of the original recipients.

Messaging Server SMTP plug-ins act at two stages in message processing:

Messaging Server 4.0 includes one pre-built plug-in, the UBE plugin (see Chapter 8, Filtering Unsolicited Bulk Email). It provides a flexible, customizable filtering capability for removing or redirecting unwanted messages.

For more information about server plug-in APIs, see Messaging Server Plug-In API Guide. For general Netscape developer information, see the Netscape DevEdge site.


Managing SMTP Plug-Ins with Netscape Console
The SMTP plug-ins that you can use with Netscape Messaging Server may include

See your Netscape sales or support representative for information about the availability of plug-ins for Messaging Server 4.0.

 As administrator, you control which plug-ins are installed and active at any given time. Plug-ins may have very different purposes, but they are all installed and activated in the same way.

 Installing Plug-Ins

Only one plug-in (the UBE plug-in) is installed automatically when you install Messaging Server. Other plug-ins come with documentation describing how to install and configure them.

Follow these steps to install a plug-in:

  1. Copy the plug-in library file to a suitable location on your server host machine.

  2. In Netscape Console, open the Messaging Server on that host machine.

  3. Click the Configuration tab and open the Services folder in the left pane.

  4. Open the SMTP icon under the Services folder, and select Plugins under the SMTP icon. The SMTP Plugins form appears in the right pane.
    5. (See SMTP Plugins Tab for a complete description of the contents of that form.)

  5. Click Add to open the Add Plugin window.

  6. In the Add Plugin window, specify the following information for your new plug-in:

  7. Click OK to commit your entries and install the plug-in.

  8. Restart the server.
See Add/Edit Plugin Window for a complete description of the contents of the Add Plugin window.

Note: Your plug-in may have additional installation procedures not described here. See the documentation accompanying the plug-in for more information.

By default, a newly installed plug-in is not active. To activate your new plug-in, see Activating and Deactivating Plug-Ins.

The information you enter in the Add Plugin window is written to your Messaging Server's plugins.cfg file. See Manually Installing and Configuring Plug-Ins for information on installing plug-ins by directly editing plugins.cfg.

Deleting (Uninstalling) Plug-Ins

Follow these steps to remove an installed plug-in from your Messaging Server, using Netscape Console:

  1. Open the SMTP Plugins form, as described in Installing Plug-Ins.

  2. In the Plugin Configuration table, select the pathname of the plug-in you want to delete.

  3. Click Delete.

    4. Note: This uninstallation removes the plug-in library file and makes corresponding modifications to the configuration file plugins.cfg. If your plug-in includes other files, you may have additional uninstallation steps to follow. See the documentation accompanying your plug-in for more information.

You can also remove a plug-in by editing and deleting files manually. See Manually Installing and Configuring Plug-Ins for instructions.

Activating and Deactivating Plug-Ins

All installed plug-ins appear in the Messaging Server SMTP Plugins form in Netscape Console. Follow these steps to activate or deactivate a plug-in:

  1. Open the SMTP Plugins form, as described in Installing Plug-Ins.

  2. In the Plugin Configuration table, locate the pathname of the plug-in you want to activate or deactivate.

  3. Check the Status box to the left of the plug-in's pathname to activate the plug-in; uncheck the Status box to deactivate the plug-in.

  4. Click OK.

    5. Note: If the plug-in you want to activate or deactivate does not appear in the table, it may not be installed or it may have been installed improperly. If it was installed improperly, remove it by following the instructions in Manually Deleting Plug-Ins, and then try again.

The active or inactive status of a plug-in is stored in the plugins.cfg file. See Manually Installing and Configuring Plug-Ins for information on activating and deactivating plug-ins by directly editing plugins.cfg.

Configuring Plug-Ins

You initially configure a plug-in when you first install it (see Installing Plug-Ins). You can also use Netscape Console to change the configuration of an installed plug-in.

Follow these steps to reconfigure an installed plug-in:

  1. Open the SMTP Plugins form, as described in Installing Plug-Ins.

  2. In the Plugin Configuration table, select the pathname of the plug-in you want to reconfigure.

  3. Click Edit. The Edit Plugin window opens.

  4. In the Edit Plugin window, modify any of the following information as needed:

  5. Click OK to commit your reconfiguration of the plug-in.
See Add/Edit Plugin Window for complete documentation of the contents of the Edit Plugin window.

The information you enter in the Edit Plugin window is written to your Messaging Server plugins.cfg file. See Manually Installing and Configuring Plug-Ins for information on reconfiguring plug-ins by directly editing plugins.cfg.

Note: Your plug-in may have additional configuration files and procedures not described here. See the documentation accompanying the plug-in for more information.


Managing SMTP Plug-Ins Manually
You are not required to use Netscape Console to manage your SMTP plugins. This section describes how to manage them by editing the plug-in configuration file.

 Manually Installing and Configuring Plug-Ins

You can install and configure an SMTP plug-in by directly editing your Messaging Server plugins.cfg file. That file is located at instanceDirectory/smtp-bin/plugins/, where instanceDirectory is the directory containing the files of the specific instance of the Messaging Server that uses the plug-in.

The plugins.cfg file holds basic configuration information for all installed plug-ins. In the configuration file, plug-ins are listed in the order in which you installed them in the Messaging Server. When they run, the plug-ins for a given entry point are also executed in that order. If order of execution is important, either make sure you install plug-ins in the order you want, or edit plugins.cfg to achieve that order.

Each plug-in's configuration is a line with these elements:

 
entry pluginPath funcs=functionList [optionList]
where the elements have the following meanings:
entry
The entry point (PostSmtpAccept or PreSmtpDeliver) at which this plug-in operates.
pluginPath
The pathname to the plug-in library's binary (executable) file.
functionList
A comma-separated list of the functions supported by this plug-in. Messaging Server calls these functions, in the order in which they appear in this list, to execute the plug-in.
optionList
An optional set of comma-separated name=value pairs that the plug-in can use for any purpose. Messaging Server passes this information to the plug-in when it executes the plug-in.

Here is a example for a Unix server with a (fictional) character-set translator plug-in:

 
PostSmtpAccept /usr/local/lib/char_xlate.so
funcs=xlate_charset
no_xlate_domain = *.fr
This plug-in acts at PostSmtpAccept, its library name is char_xlate.so, it has a single function (xlate_charset), and it uses a single option that tells it not to translate messages from the top-level domain .fr.

 Here is an example for a Windows NT server with the UBE filter plug-in:

 
PostSmtpAccept i:\Netscape\Server4\msg-Airius1\
   smtp-bin\libUBEfilter.dll
funcs=filter_msg_plugin config=i:\Netscape\
   Server4\msg-Airius1\smtp-bin\plugins\UBEfilter.opt
option=i:\Netscape\Server4\msg-Airius1\smtp-bin\plugins\UBEfilter.opt
This plug-in also acts at PostSmtpAccept, its library name is libUBEFilter.dll, it has a single function (filter_msg_plugin), and it uses two options (named config and option) that specify pathnames to configuration files.

 You can modify the information in any of these lines to change the configuration of the plug-in. For example, if you change the location of the plug-in library file, you can enter the new path here instead of using the Netscape Console interface. (This would be equivalent to reinstalling the plug-in, and would require a server restart.)

 If a plug-in is installed but has been deactivated through Netscape Console, its line in the plugins.cfg file is commented out; that is, it starts with a number sign (#) character. You also can manually deactivate a plug-in by commenting out its lines in the file.

Note: If your plug-in uses other files besides its library file and plugins.cfg, configuring the plug-in may mean editing those files as well. For details, see the documentation that accompanies your plug-in.

Manually Deleting Plug-Ins

To manually delete, or uninstall, a plug-in, take these steps:

  1. Deactivate the plug-in if it is active.

  2. Delete the plug-in's lines from plugins.cfg

  3. Remove the plug-in library file from your server host machine.

  4. Remove any other plug-in-specific configuration files, as noted in the documentation that accompanies the plug-in.

Interface Reference: SMTP Plug-Ins
This section describes the Netscape Console interface elements that allow you to install and configure SMTP plug-ins. See Managing Servers With Netscape Console for information on using Netscape Console to manage Messaging Server and other servers.
SMTP Plugins Tab
You use the form accessed through this tab to install and remove SMTP plug-ins. For more information, see also

 The SMTP Plugins form has these elements:

 Plugin Configuration. This table displays the status and location of each installed plug-in. Use the Path entry to select a plug-in; then use the Add, Edit, and Delete buttons to add it, delete it, or change its configuration.

Note: If you have installed a plug-in but it does not appear in this field, it may not have been installed properly. In that case, remove it by following the instructions in Manually Deleting Plug-Ins, and then try again.

Status. Check this box to make an installed plug-in active; uncheck the box to make an installed plug-in inactive.

 Path. This entry within the Plugin Configuration table displays the path to (location of) each installed plug-in. To edit this entry, select it and click Edit.

 Add. Click this button to open the Add Plugin window (see Add/Edit Plugin Window), which allows you to install a new SMTP plug-in.

Edit. After selecting a plug-in in the Plugin Configuration table, click this button to open the Add Plugin window (see Add/Edit Plugin Window), which allows you to edit the configuration of the selected plug-in.

Delete. After selecting a plug-in in the Plugin Configuration table, click this button to remove the selected plug-in.

 Action Buttons

Save. Click this button to commit any settings you have made in the SMTP Plugins form.

Reset. Click this button to return the form to the settings it displayed when you opened it (unless you have previously clicked Save, in which case the form returns the settings it had when you last clicked Save).

 Help. Click this button to get online help (this document) describing the SMTP Plugins form.
Add/Edit Plugin Window
You use this window to install a new SMTP plug-in or edit the characteristics of a currently installed plug-in. For more information, see also

 The Add/Edit Plugin window has these elements:

 Entry. Use this list to select the entry point (PostSmtpAccept or PreSmtpDeliver) for this plug-in.

Path. Use this field to enter the location of (path to) the plug-in library itself. You must have already placed your plug-in library in its location before entering this information.

 Functions. Use this field to enter the list of functions that this plug-in implements. The list is a comma-separated sequence of function names. The documentation accompanying the plug-in you are installing or reconfiguring should provide this information.

 Options. Use this field to enter additional information (in the form of comma-separated name=value pairs) that is to be passed to the plug-in when it is executed. The documentation accompanying the plug-in you are installing or reconfiguring should provide this information.

Action Buttons

OK. Click this button to commit the information you have entered, installing the new plug-in or imposing the changes you have made to the existing one.

Cancel. .Click this button to close the Edit Plugin window without making any additions or changes to the current set of plug-ins.

 Help. Click this button to display online help (this document) that describes the Edit Plugin window.

 

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