Like I said in the title this may already exist but if it does I forgot about it. If it desnt then it will be a relatively quick fix.

I know we have all tried to send a message and have had the dreaded inbox full message. Instead of having to rely on and wait for them to realize the problem perhaps the site can send a notification that someone is trying to contact them.

Perhaps tell who is but limit it to that one notification per sender to receiver so they can appropriately respond if they choose. And limit it to the notification.

This will add a very useful feature while eliminating a sometimes irritating issue and limiting potential strain on the servers.

I hope I adequately describe what I see as an easy fix to a minor but somewhat frequent irritating issue for regular / daily users.