Sure, it's actually exactly what the domain name suggests. You need an hn account to sign up* and then you can write personal messages to other (signed up) user

Sure, it's actually exactly what the domain name suggests. You need an hn account to sign up* and then you can write personal messages to other (signed up) users. *the registration process requires you to put a key into your public profile, to make sure it's your account. This key can be removed once signup is completed. There is no need of an email and i do not collect any data whatsoever.