[sylpheed:37264] right-click: remove from server if still there?

All my desktop systems use Sylpheed and when any of them collects
mail from the providing mail server the messages get deleted as per
Sylpheed preferences. My otherwise identical but transient-use laptop
systems LEAVE the messages on the server. A minor issue with this
arrangement is that each time I check messages from the laptop I
download them all including previously downloaded ones. What I'd like
to see is a right-click menu on individual message headers allowing
only THEM to be removed from the server when using the laptop. This may
be waaaaaaay too much to expect so I'm not even asking, just floating
the idea in case it would be an easy code-edit (I know, there's no such
thing as an easy code-edit).

Cheers