I have a basic Sieve interpreter in Rust here, if you're interested: https://crates.io/crates/libsieve https://crates.io/crates/libsieve It's not very featuref

I have a basic Sieve interpreter in Rust here, if you're interested: https://crates.io/crates/libsieve https://crates.io/crates/libsieve It's not very featureful or well-tested, but it does work for my own use (personal e-mail server).