Is the mail account accessed from anywhere else? (phone, tablet, another person et al.) Shift and delete will permanently remove an email by deleting and bypassing the trash, but only if it has focus, so you have to have managed to press keys to return to the source email. But that still does not explain the disappearance of the pasted information. Just a suggestion. I have no idea if it will help, but try using edit as new message in circumstances you mention. It will populate the write with the message, and all of the addressing information. Another option is to customize the toolbar in write to include the quote icon. (right click the bar and select customize. drag the quote marks from the opened panel to the toolbar in write.) Clicking the quote will insert as a quote the current selected message in the message list. Note that is you select a part of the message text in the reading pane on the list windows then only the selected text will be quoted. I am just trying to remove the paste part of the equation... Perhaps a Ctrl +Z is occurring and you are undoing the paste.