Hi,

>>>>> In <84k7crxvlw.fsf@lucy.is.informatik.uni-duisburg.de>
>>>>>	kai.grossjohann@gmx.net (Kai Großjohann) wrote:

> Messages marked `E' are supposed to be expired, *except* if
> nnmail-expiry-wait or nnmail-expiry-target say something else.

> So, actually, Gnus seems to have had a bug before that was now
> fixed...

I've made the following change in T-gnus (based on Gnus, using
SEMI and FLIM for MIME functions):

1999-01-18  Katsumi Yamaoka  <yamaoka@jpl.org>

	* gnus-sum.el (gnus-summary-move-article): Don't copy expirable
	marks if the destination group is not expirable.

Here's a patch for the recent Gnus.  How is it?