1.0Dundee Internet Serviceshttps://dundee.netPathttps://dundee.net/index.php/author/pat/rich600338<blockquote class="wp-embedded-content" data-secret="Xn9JHlO4dr"><a href="https://dundee.net/index.php/subject-line-science/">Subject Line Science</a></blockquote><iframe sandbox="allow-scripts" security="restricted" src="https://dundee.net/index.php/subject-line-science/embed/#?secret=Xn9JHlO4dr" width="600" height="338" title="“Subject Line Science” — Dundee Internet Services" data-secret="Xn9JHlO4dr" frameborder="0" marginwidth="0" marginheight="0" scrolling="no" class="wp-embedded-content"></iframe><script> /*! This file is auto-generated */ !function(d,l){"use strict";l.querySelector&&d.addEventListener&&"undefined"!=typeof URL&&(d.wp=d.wp||{},d.wp.receiveEmbedMessage||(d.wp.receiveEmbedMessage=function(e){var t=e.data;if((t||t.secret||t.message||t.value)&&!/[^a-zA-Z0-9]/.test(t.secret)){for(var s,r,n,a=l.querySelectorAll('iframe[data-secret="'+t.secret+'"]'),o=l.querySelectorAll('blockquote[data-secret="'+t.secret+'"]'),c=new RegExp("^https?:$","i"),i=0;i<o.length;i++)o[i].style.display="none";for(i=0;i<a.length;i++)s=a[i],e.source===s.contentWindow&&(s.removeAttribute("style"),"height"===t.message?(1e3<(r=parseInt(t.value,10))?r=1e3:~~r<200&&(r=200),s.height=r):"link"===t.message&&(r=new URL(s.getAttribute("src")),n=new URL(t.value),c.test(n.protocol))&&n.host===r.host&&l.activeElement===s&&(d.top.location.href=t.value))}},d.addEventListener("message",d.wp.receiveEmbedMessage,!1),l.addEventListener("DOMContentLoaded",function(){for(var e,t,s=l.querySelectorAll("iframe.wp-embedded-content"),r=0;r<s.length;r++)(t=(e=s[r]).getAttribute("data-secret"))||(t=Math.random().toString(36).substring(2,12),e.src+="#?secret="+t,e.setAttribute("data-secret",t)),e.contentWindow.postMessage({message:"ready",secret:t},"*")},!1)))}(window,document); //# sourceURL=https://dundee.net/wp-includes/js/wp-embed.min.js </script> ou can find studies on Subject Line structure, the use of capital letters, character set utilization, informal or formal wording, long or short Subject Lines and whatever else is deemed to have an impact on the open rate statistics.