Full text search multiple mailboxes

A client needed to full-text search through user-data: directories and mailboxes. They had a Microsoft setup with Outlook / Exchange. I searched around, and for now found:

- ExMerge,
- Lookeen, and
- (free!) Search Server 2008.

A friend working as a digital detective told me they use X1 for investigating work stations (including searching free clusters), DTsearch, and Encase and Forensic Web Search for LANs.

PWC pointed to:
- Paraben
- Ontrack Powercontrols

Anybody with better solutions, please let me know.

I believe Windows Indexing Service does not out of the box search pst files. And i'm to up to the point (but have been looking at) search appliances (compared). Also found AimAtFile (and others, like open source ixsf), but those tools seem unneeded if we can one of the earlier mentioned working.

Image source: http://www.microsoft.com/enterprisesearch/en/us/search-server-express.aspx .