I've not been a complete idiot, I've been making semi-regular backups of the mail files on my server - however, these tend to be unfiltered so I've got the fun of extracting only the emails I want. Except I discover that I don't have anything between 2002 and July 2005 - I just hope there wasn't anything important in that lot (only last week I was thinking of exporting all my mail from Turnpike and seeing about a new mail client, preferably one that doesn't store all the mail in one humongous binary file).
And to put the cherry on the cake, my service provider's main building was struck by lightning at some point yesterday and I can't connect to any of my sites.
Actually, I've just had a thought. Because I need to access the contents when away from home, the mail folder I lost the contents of is the only one I have that does the pop3 mirror thing rather than simply slurping everything down. If something happened to the mail on the server, would Turnpike mirror this by killing the copies at home?
The moral, which of course shouldn't need repeating, is : back up early and back up often!