[Magdalen] What's up with this?

[Grace Cangialosi]

All of a sudden some of my mail from this group is turning up in the junk folder--not all of it, but often the first post in a new thread, so I have no idea what subsequent posts are referring to.
Does anyone know why this happens or how to fix it? I use gmail for this list. This seems to happen periodically and then stops without any action on my past...