Sieve is great, but the proton mail implementation is severely limited by the inability to search message content, such as body. This is of course by design, sieve is running on the encrypted emails, so it cannot read the body content, however, it would be nice to do this sometimes. In a similar vein to the local side body search implemented by proton, I propose a client side sieve implementation, that can run in desktop proton to do filtering on unencrypted message content.