Hi Severin, Which version of Mail are you using?
"White" mailboxes are mailboxes that don't contain messages. This type of mailbox can exist after importing messages from another mail client. I am surprised if you can drop messages into such mailboxes! If you do a "search" for one of the vanished messages, does it appear? Mail stores messages in individual files so that Spotlight can index them. Anyway, to help you on your way to rectifying this problem... 1. Open a new window in the Finder, and go to your home directory (which is usually the default location for a new window anyway). 2. Then, go into the Library folder and then the Mail folder. You should see lots of extra folders corresopnding to your accounts. 3. If your white mailxboes were creates as "Folders On My Mac", then find the Mailboxes folder and open it. 4. You should see a few things. One is that there will be a folder for every white and blue mailbox. The next is that there is a ".mbox" folder for every blue mailbox. This distinguishes white mailboxes from blue mailboxes. (You can freely create or delete these ".mbox" directories to convert between white and blue. However, don't delete them because they contain all your mail!) 5. Can you report whether your white mailbox has an ".mbox" folder, and if so whether there are files within it. Within the .mbox folder there will be an Info.plist file and a Messages folder. Within the Messages folder there will bea file for every individual message. Have you found anything, or can you tell us "what you see"?
