program for indexing & searching email
mairix is a program for indexing and searching email messages stored in Maildir, MH or mbox folders, or on an IMAP server. (Note that TLS support is currently disabled due to a problem with certificate validation, so it is recommended only to use this on localhost). The search mode populates a "virtual" folder with symlinks which point to the real messages which can be opened as usual in your mail program.