Plug-In for Procmail
offers a unique, directed solution to special needs in personal
email management on
a *nix platform. A text-based, modular script plug-in for the widely
used procmail mail
(mda), vsnag brings the power of regular expressions to focus
in combatting common viruses and worms or suspect email file attachments
generally. User licenses are granted free of royalty (but please
see specific limitations in the license
agreement; the code itself is not public domain!).
Easily configured;“small-footprint” friendly
Written with the twin goals of maximum user flexibility and "turn-key"
plug-in simplicity, vsnag is coded "small" to be friendly
to your host machine's processor table and memory. In normal operation
vsnag invokes native
procmail instructions only, with no outside calls or
Wherever it can, vsnag limits its scouring algorithms to the message
headers and declines to shove entire
message bodies “down the pipe.” Virus Snaggers brings
the user an organized, efficient approach to banishing pernicious
mail messages from the inbox. Retake control of your email — plug
it in and go!
Version 2 has been completely recoded!
We've gone painstakingly through every line of code from the
version and made it better than ever. Efficiency, accuracy, and
improved flexibility were our watchwords. We think you'll agree
that Virus Snaggers, ver. 2, is the best idea around for augmenting
the safety and usability of your *nix-based email server or host.
Virus Snaggers is now packaged in modular form. There are three
code files and one documentation file. The files can be placed
where you choose.
The three programmatic files comprise the main module and two
environmental modules. For best results, edit the
"myvars" file according to the documentation. Then point your
existing .procmailrc file at vsnag, and go! See the documentation
and FAQs for more details.
List of Changes:
The following are only highlights. See the documentation file
for more comprehensive discussion of the new package and its changes.
- Improved flexibility with all-recoded algorithms
- Simplified customization: set all options in one file
- Stepped ZIP scouring according to your preferences
- Custom logging or other post-processing via optional hook rc-file
- Extension blocking easier to customize
- Documentation expanded and FAQ added
- Free mailing list for community support & discussion
- Virus signatures are gone, replaced with “Smart Classification”
- Testing for encoded filenames with ver. 2.22+
- Enhanced diagnostic toolset helpful to all procmailers
- 5-Jan-2005: Version
2.23 released. There are a number of enhancements; check “What's
- Vsnag package includes a custom-coded point-n-shoot shell
script for testing and diagnostics.
Read the license agreement
Click on the Legal link
and look it over to your satisfaction, please. Downloading Virus
Snaggers presumes your agreement with what's here.
Download the package
Click on the Download link and select either the gzipped tarball
or the zip-format version. (The contents are identical.) Uncompress
the four files on your *nix system wherever you'd like them to
Edit myvars as needed
Your editing should be limited to one file! Use a
*nix-compatible editor to customize the myvars file
if you wish. (If you've placed vsnag's modular code files in separate
locations, you'll need to say so inside myvars.) In
any case, review what's in that file: it lists all variables that
found in the vsnag documentation file.
Call Virus Snaggers from your .procmailrc
You will edit your existing .procmailrc file to call vsnag. Use
a line such as the following:
INCLUDERC = /your/path/to/vsnag.rc
Be sure to check for proper operation and mail delivery before
walking away from your system!
Note to system administrators
If you're calling vsnag from a systemwide /etc/procmailrc, we recommend that
you use a
DROPPRIVS statement prior to the call to vsnag.
DROPPRIVS=yes, along with whatever logging
or other options you wish, in a separate hook file that vsnag can
now run. See documentation for