Even after everything discussed in this thread, you still decide to go ahead and do it? We'll, here's hoping you only committed a small amount of bitcoin, since if anything happens with Google or your receiving email provider, or they discontinue the service, or even just a minor bug, your coins are lost forever.

If you really wanted to irreversibly lock up some coins, then just sign a timelocked transaction to yourself and delete the relevant private key. Still a stupid thing to do, but far far safer than trusting an unknown number of intermediary third parties.