From Wasya Wiki
email validation regex (js)
/^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/
email validation regex (ruby)
/\A[\w+\-.]+@[a-z\d\-]+(\.[a-z\d\-]+)*\.[a-z]+\z/i
Email tracking
From: https://developers.google.com/analytics/devguides/collection/protocol/v1/email From: https://dyn.com/blog/tracking-email-opens-via-google-analytics/
<img src="https://www.google-analytics.com/collect?v=1&..."/>
URL Component Explanation v=1 Protocol version within Google Analytics tid=UA-12345678-1 Your Google Analytics Tracking ID cid=CLIENT_ID_NUMBER A systematic tracking ID for the customer t=event ells Google Analytics this is an Event Hit Type ec=email The Event Category helps segment various events ea=open The Event Action helps specify exactly what happened el=recipient_id Event Label specifies a unique identification for this recipient cs=newsletter Campaign Source allows segmentation of campaign types cm=email Campaign Medium could segment social vs. email, etc. cn=Campaign_Name Campaign Name identifies the campaign to you