I don't know how it works in other countries, but at least in Germany, the judiciary essentially provides this service: When you have your will notarized, they will offer to send a copy to the district court who will keep it safe until you die, at which point they will retrieve it to decide what happens to your inheritance. As far as I know, you can also put non-inheritance related things in there, including asking people to forward messages (in sealed envelopes, if you wish) on your behalf.<p>In countries with this kind of system, the only use case I can imagine for an additional commercial e-mail based service is if you don't trust your next of kin at all, so you don't want to leave the message forwarding up to them, or have messages whose recipients you want to keep secret from them.