How do I use ClamAV with getmail?
You should also read this message in the getmail users’ mailing list archives and the ClamAV documentation if you want to use ClamAV with getmail. ClamAV, like SpamAssassin, can by used in standalone or client/server configurations. In either case, you need to add the StreamSaveToDisk option to your clamav.conf file to enable scanning from stdin.