MILTER, Mail Filter API for sendmail

MILTER, sendmail's Mail Filter API, enables third-party programs to access mail messages as they are being processed to filter meta-information and content. You do not need to build the filter and configure sendmail to use it. This API is enabled by default in version 8.13 of sendmail.

For more details, see the following:

• http://www.sendmail.org/

• http://www.milter.org/