"Save attachments" button in Mail has disappeared

My "Save attachments" button in Mail (6.6/1510) disappeared the other day. It has always been there, sitting on the dividing line between message header and message content. But now it's gone. All of a sudden.

Sure, it becomes visible if I select detailed header info, but it should be there even with the simplified header view. At least it has been up to a few days ago.

Any tips on how I get it back? It's a bit annoying to select detalied header info each time I want to save attachments. Dragging and dropping is no option for me, since part of what I want is to se a list of all attachments. The "Save" button provides that feature.