conv2047 is a very simple RFC 2047 Unicode email header field converter. It reads header lines from standard input and tries to decode or encode them. Operation modes: -d decode (MIME-Header --> UTF-8) and -e encode (UTF-8 --> MIME-Header). The -c option can concatenate multiple output lines into 1.
SpamCheetah is a network-level spam filtering solution built around OpenBSD greylisting, tarpit, and blacklisting. It comes with a Web interface and requires zero administration. It does not allow spam to even land in your network, thus saving you precious bandwidth. It does not have the 'false positives' problem of losing legitimate mail.