renattach is a fast and efficient e-mail stream filter written by Jem
Berkes. It can rename or delete potentially dangerous attachments or
even eliminate entire messages to help sites deal with resource strains
caused by virus floods. Unlike conventional virus scanners, there are no
specific virus or worm definitions. Instead, attachments are classified
based on file extension and executable encoded body content.

Features
- Fast, efficient, lightweight, little overhead, pure C code
- Recognizes both MIME and uuencoded attachments
- Compliant with RFC2047 and RFC2231, handles encoded filenames
- Capable of reading filenames inside ZIP archives, on the fly
- Can rename or delete attachments, or kill entire messages
- Can detect executables that carry DOS/Windows signature
- Supports list of banned filenames (great for handling floods)
- Simple pipe/stream operation; can be used within many filtering systems
- Can be used directly as a content_filter for Postfix MTA
- Can be installed as a local delivery agent for Sendmail MTA

WWW: http://www.pc-tools.net/unix/renattach/