Possible SquirrelMail bug

In tracking down some mail problems that my users were having, I think I may have found a serious bug in Apple’s out-of-the-box configuration for SquirrelMail. Could someone see if they can reproduce this so I can make sure it’s not due to something I did?

It’s pretty easy to test. But don’t do this with an actual user account, because it messes it up pretty bad, and it’s hard to fix. Use a throwaway test account.

Here’s the steps I did:

1. Create a user with login "billg". Enable IMAP e-mail for that user.
2. Log in to SquirrelMail with login "billg". Send a few test messages to billg, and watch them show up in the inbox. Launch Server Admin and see that there’s a mailbox called "billg".
3. Log out of SquirrelMail.
4. Log in to SquirrelMail with login "BILLG" and the password for billg. Notice that all of the test messages you sent earlier no longer show up in the inbox. Launch Server Admin and see that the mailbox "billg" is gone and has been replaced with "BILLG".

Since I had cyradm installed, I checked and found that there were now two sets of mailboxes, half called "billg" and half called "BILLG". Further confusing things, both mailboxes were apparently using the same directory in the filesystem, with the result that if I used cyradm to delete one mailbox, attempts to access the other resulted in I/O Errors.

I didn’t experiment too much to see which mailbox mail wound up going to once both mailboxes were in place, but it apparently did cause some routing problems because I was alerted to this problem by users who were having erratic mail behavior. The main problem was that a user would suddenly find his inbox empty of all saved messages, even though the messages were still visible in the file system. Using the cyrus "reconstruct" utility wouldn’t recover them.

The fix in our case was to go to /usr/share/squirrelmail/config/config.php and change a line so that $force_username_lowercase = true. This causes the login to be transformed to lowercase, which prevents the mailbox corruption from occurring.

Our system is running Mac OS 10.3.5. SquirrelMail’s version (at least, the one at the top of config.php) is 1.4.0.