To verify custom data, in osx,
in chrome inspector, copy the customData value, from the querystring in headers,
run the command in osx terminal
pbpaste | base64 -D -
To test opt out feature, first click here, then send a test message, and look for an optum_analytics_optout cookie, if it's present, your requests should not show up in kibana. To reset, delete the click the link again and delete your cookie.