So is Aero going to have decentralized email or just instant messaging, because there IS a difference. I think email is alot more useful personally being it doesn't require the other person to be online or have the same program.
Also all these so-called anonymous email services in theory may be fine but they are still centralized and if a bad actor gains control of the master keys for the encryption they are compromised.
From Dan's (atcsecure) Review:
"E-Mail expire after 48 hours". So I would say it's not instant Messaging but a real email where the other Person hasn't to be online. The other Person only has to be online once every 48 hours.