Finding email with Strigi in .tar backups

Now that my CUBIC desktop machine is shutting down, I made the necessary backups, among a mail.tar for my mail correspondence of about a year. About 500MB in size for almost 8700 files. Strigi is a perfect tool to help me find messages in this archive, as it will recurse into the .tar archive, and even into email attachements. I created an index just for the archive with:

strigicmd create -t clucene -d index/ mail.tar

It took Strigi about 30 seconds to index the whole archive. That's good performance!

Now, Strigi indexes content full text, but also uses a controlled vocabulary (among which one specifically for chemistry). So I can search for email messages which have article in the subject with:

strigicmd query -t clucene -d index/ email.subject:article

However, From: and To: content was not yet extracted. That was easily patched. This allows me to find correspondence between me and, for example, Christoph:

strigicmd query -t clucene -d index/ email.to:Christoph AND email.from:Egon