1.0Dundee Internet Serviceshttps://dundee.netJanethttps://dundee.net/index.php/author/janet/rich600338<blockquote class="wp-embedded-content" data-secret="QsqcJCK5b5"><a href="https://dundee.net/index.php/email/">Email Delivery Explained!</a></blockquote><iframe sandbox="allow-scripts" security="restricted" src="https://dundee.net/index.php/email/embed/#?secret=QsqcJCK5b5" width="600" height="338" title="“Email Delivery Explained!” — Dundee Internet Services" data-secret="QsqcJCK5b5" 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> The MX server has specialized software for distributing mail. To determine the destination of the email, the mail delivery agent (MDA) reads the header and determines if the email should remain on its own server or send over the internet to a remote server.