- [x] ignore .overview when grepping Gnus folders
- [x] implement inverted matching
- [x] re-implement recursive search through directories
- [ ] implement literal date matching
- [x] write Texinfo documentation
- [x] implement writing selected messages to a new folder
- [x] implement deleting selected messages
- [ ] add support for config files
- [x] add support for reading messages from stdin
- [x] add support for compressed mbox folders
- [ ] make use of lockfile library
- [ ] make use of Solaris' maillock library
- [x] provide possibility to use flock() instead of fcntl()
- [ ] provide national language support with gettext()
- [x] allow run-time selection of file locking method
- [ ] make mboxgrep understand MIME
- [x] enable removing duplicate messages w/ MD5 checksums
- [ ] add checking for conflicting command-line options
- [ ] add support for GnuPG
- [x] add support for bzip2 compression
- [ ] add support for mail folder conversion