Omeka/Contribution plugin already sends an email to a user confirming that they have contributed an item to the collection. However, like most sites, we make the items private so that we can moderate content a little bit (make sure its related/not spam/not too vulgar).
I was wondering how I might make it so that our site sends a second confirmation email when their item has been made public by an administrator.
You could probably do this with a plugin, using the hook for after an item has been saved. You'd probably want to check to see if that item has a contributor associated with it, and send an email to that contributor. Have to dig around in Omeka a bit for this, but it seems perfectly doable to me. It might help to see how the Contribution plugin does it, looking at its controller for Contribution records, specifically its send email method.
Might be a useful enhancement to add to the Contribution plugin.