User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322) Build Identifier: Mozilla Thunderbird version 1.0 (20041206) I created a new subfolder called "H.I.C." Key thing to note: PERIOD at the end of the folder name. (Innocent enough, so I thought.) I created several subfolders under "H.I.C." and put new messages in them. Two things happened: 1) While Thunderbird was still running, I was not able to see the subfolder contents of a neighboring subfolder when using the "Message->Move" option. 2) More importantly, after exiting and restarting Thunderbird, ALL OF THE SUBFOLDERS WITHIN "H.I.C." disappeared. What was left was an empty folder named "H.I.C" (without the trailing period). After almost panicing and getting ready to abandon Thunderbird, I discovered that no one else had reported this problem, and millions of people use Thunderbird (well, at least a lot). So I took a look at the raw Email folders on the hard drive and found the problem. There were both "H.I.C" and "H.I.C." folders. I renamed the correct one to "H I C" and got rid of the bad one, restarted Thunderbird, and it fixed everything. Thank God! I'm SO GLAD Thunderbird has an "open" file format! Reproducible: Always Steps to Reproduce: 1. Create a new account sub-folder called "H.I.C." (without the quotes) 2. Create one or more sub-folders within that sub-folder 3. Add new Emails to the innermost sub-folders 4. Exit & Restart Thunderbird. Actual Results: The innermost sub-folders are gone!! Expected Results: Either of two things: 1) Not corrupted the sub-folder, obviously, OR 2) Prevented me from entering a folder name that ended with a period With millions of users using Thunderbird, a few of them are going to attempt to create a folder name that ends with a period. This bug will cause a big headache for those users. The good news is that it should be extremely easy to fix this bug if you opt for the easier method of just preventing the user from entering a folder name that ends with a period.

DUP of Bug 117840. See Bug 229522 for patch. See dependency tree of bug 124287 for other folder name related problems. ( https://bugzilla.mozilla.org/showdependencytree.cgi?id=124287 ) *** This bug has been marked as a duplicate of 117840 ***