Great news, Honest Mobile is compatible with HulloMail!
To enable HulloMail, download the app and sign up. When choosing your network, choose Three.
To activate HulloMail, use the Activation Number stored in your phones contacts by Hullo Mail
To deactivate HulloMail first dial ##002# or ##004# and then dial 1211. This will restore your default Honest Mobile Voicemail.