Blank emails dated 12/31/1969 appear in local folders on Thunderbird after I move email messages into the folder. this happens as follows: 1) while in InBox I go to Edit/Find/Search Messages 2) I search, for example for a particular sender 3) Then I highlight some of the found messages, click Move To at the bottom of the search window, and navigate to the folder where I want to move the messages, The target folders are always subfolders under Local Folders, sometimes a sub-subfolder. After several seconds the messages are moved to the target folder. 4) The messages move to the target folder, but one or more of the blank messages also appear. For example I just moved seven messages to a subfolder, and 11 blanks also appeared. I just searched my Local Folders for messages dated 12/31/1969, and there are 107 of them scattered among four different subfolders. These blank messages show in the count for the number of unread messages in the folder. The blank messages can be deleted with the Delete button on the search box. That moves them into the Local Folders Trash folder. I currently use Thunderbird 45.3.0, but this problem has existed for several years, through many versions of Thunderbird.