All the transfers are implemented within the Ethereum blockchain. No tokens - only Ethers are used. The Ethers are transferring directly to your address, right after the payment is confirmed by the miners. If the sender doesn't have enough funds/don't know about ETHletter - don't worry, we will respond him with the instructions and description. The sender doesn't need to sign up at the ETHletter service - he just needs to top up his balance with one click.

You can easily use ETHletter within the web-interface. Or you can set up your favorite mail client - Thunderbird, Outlook, etc. Also, you can set up the email forwarding, so you don't even need to use your ethletter email directly.

The service is free, no limits on emails or any other pitfalls https://app.ethletter.com