Let me start by saying that this is a low priority feature request. It is not necessary, it's only a helpful gadget, and I have no idea how hard it would be to code, but it would be nice if it was possible to mark messages as unread to remember to read them later on.
That's already implemented, at least on Dwilight and Beluaterra. Just click the yellow feather (?) left of 'reply', and the message is saved :)
Wow, I never saw that before! Silly me.
Thanks!
Note that the message is not "saved". It is only marked for future reference. It will still expire in 30 days, just like every other message.
Indeed, maybe we should consider moving it to stable. :)
There's a lot of things I'd like to see on stable, including this, the delay arrival button, the new message searching code...(grins)
This is on stable, and has been for a while. I've got a message marked on my EC character already, in fact.