If opening a new mail, attaching a file, it is possible to open this
attachment inside this mail-window (rightclick-edit) and change it,
close the app (like word) and changes will be in the attachment.

But if I open the mail, attach a file, the pause this mail-job, saving
it into 'work in progress' and than reopen it inside this folder, I'm no
longer able to change the attachment. I still can open word inside the
mail and cahnge the file, but if closing word and look into the
attachment I'll find my changes are gone.

Can someone copy this problem?