I have been developing a utility to to automate the process of forwarding emails to an ISP's (PlusNet's) spam training addresses. In theory such a utility could be used for any ISP that utilises a similar process.
Links:
FastForward page
FastForward guide (for version 1.0.5)
Downloads:
Version 1.2.8 - Postini header analysis tweaks, spoof email reporting, progress bar and optional confirmation message
Version 1.2.7 - Postini header analysis
Version 1.2.5 - bugfix for attachments in OE
After a fair amount of testing the software in private (thanks to the RT staff who participated), it's time to open the doors to the public
Please read the readme file fully (especially the disclaimer) before you use the utility. Also, please consult the dependencies file if you run in to problems, before asking in this thread.
All feedback, comments, suggestion etc are welcome

Please bear in mind, that it might not be possible to implement every single suggestion
Notes:
This post will be updated on a regular basis during development and links to previous versions will be removed to ensure people are using the latest version.
History:
Version 1.0.14 uses the Redemption Library to send emails for Outlook
Version 1.0.15 uses the CDO.DLL to send emails for Outlook
Version 1.0.16 basic support for Eudora, uses Winsock to send emails for Outlook
Version 1.1.0 - basic support for Incredimail, incorporates many user suggestions
Version 1.1.1 - revamped GUI
Version 1.1.2 - a few bugfixes
Version 1.1.3 - includes illustrated help file, OE image check skip
Version 1.1.4 - includes option to copy email body to the clipboard
Version 1.1.6 - a few bugfixes (wizard working with Eudora)
Version 1.1.7 - improved OE identity handling
Version 1.1.8 - handles signatures in OE and now the "Send as HTML" setting is stored in the INI file
Version 1.1.9 - supports deletion after forwarding and handles multiple email selection in OE and Outlook
Version 1.1.10 - bugfix for multiple selections in OE/Outlook
Version 1.1.11 - bugfix for multiple selections with toolbar in OE
Version 1.2.0 - includes new PlusNet target emails
Version 1.1.9 - supports deletion after forwarding and handles multiple email selection in OE and Outlook
Version 1.2.1 - reverts to DSpam target addresses
Version 1.2.2 - supports sending as attachments and the new Postini target addresses
Future (planned) features:
Support for Eudora (done) and Incredimail (done)
Alternatives to using the Redemption component (done)
Anti-Phishing email features