Comment An opportunistic and little-known software utility outfit has stuck another carving knife into Thunderbird 3.

The Performance Protector blog reckons the once-reliable email client has the profile of a virus. Let it loose on your systems, and wave goodbye to network performance and any spare CPU cycles.

Fair criticism? Yes and no. PerfProtector highlights two factors for the stress Thunderbird 3 imposes on a PC. One is that version 3, unlike version 2, downloads the full contents of IMAP folders by default.

The other is that it then creates a full text index of the material, but does so very inefficiently. Gmail seems to provide a perfect storm, as folders are downloaded several times.

Still, other systems such as Mac's Mail.app and the Vista-rized version of Outlook Express (including Live Mail) also produce a full text index, but do so considerably more efficiently in their use of CPU and RAM resources.

Something has gone seriously wrong with Thunderbird. A year ago, the only criticism you ever heard about it was that development moved too slowly. Nothing ever happened, it seemed.

Back in June we pointed out that the version 3.1 beta was noticeably faster, it that 1GB of RAM is now recommended, with 768MB as a system minimum.

This is quite bizarre. The Mac OS X mail client is hardly the fastest in the world, or the most efficient: but with several Gigabytes of email stored and indexed, and a few dozen virtual folders, it takes up 128MB of RAM.

At least with open source, you can see what the developers are up to - or not.

One lingering culprit has been found - the database file format that dates back to 1994, Mork. A bug filed back in August 1999 requested de-Morking at least part of the software's reliance on Mork, and 3.0 promised to implement it. Alas, the message files are still in Mork format.

A while ago I wrote an old bugger's whinge about the state of email clients in general. I realise this is now a minority interest. Do I need to update it?