How are Ryanair collecting the E10 depature tax?
I travelled Aer Lingus last week, and there was no mention of departure tax on their website either. And there was nobody at Dublin airport collecting it, unlike Knock, where someone does. I think it just got included in the price quoted, under the general heading of taxes and fees, e.g. total inc taxes €xxx. That is very likely where Ryanair deal with it.