Are email upgrades valid on the lowest fares where you have to pay for seat? I got one email lately but I was unable to upgrade it. Upon clicking on the link (immediately after I got email), there was a system message showing up about inability to upgrade. It was also the first time I got such email for 2pax+1kid booking.
Also what about 3rd party flight bookings? Does EK sends such upgrade emails for bookings made not directly via them?