Despite setting my mail to keep a copy of sent messages in the sent folder,  some of them are not showing up.  Seems that all from my daughter do that and when I delete them......her message will be there with a little triangle in front of her name.....a few others show up that way too and any of them do not show up in the sent folder when I reply......it just started to do this about 2 months ago.  I tried to restore my computer to an earlier time but Windows 7 does not go back very far to enable me to do it.....how can I fix it?  Exactly what are those triangles in front of some of my messages in the sent and delete folders? Help help,  I can't stand this!

[Moved to Windows Live Mail - NB]