A while ago I added a file to the devel CVS branch, config/configtest.php.
The purpose of this script is to do a couple of basic checks on a
SquirrelMail install to point the administrator to common errors. It
checks things like paths and permissions, connections, PHP version etc.
You access it with your browser.
Please test it. I'd like to hear of any more tests that could be useful,
and of course whether it behaves like expected on your install. The script
could help admins new to SquirrelMail to quickly identify problems, and to
reduce support requests. Would be nice if it could be included in the next
1.5 release and - when well tested - maybe backported to 1.4 aswell.