For some of our users, their SMTP connections are being denied, with:
902 Host names have more than one DNS label
This error appears to come from https://codeclimate.com/github/msimerson/Haraka/plugins/helo.checks.js/source
I don't know how to walk them through finding out what HELO their device is sending to validate it, but it seems related to the plugin.cfg.reject.valid_hostname setting. Did this change in 5.0.3 ?