Questions Regarding HTML Emails

Table of Contents:

HTML Idiosyncrasies


(warning) If your HTML Email contains a CSS comment and inside that comment is a tag (see tag below: <code _tmplitem="277" >) then the email will render empty in Hotmail ISP including!!

<style type="text/css">
    /* This most probably won\'t work in all email clients. Don\'t include <code _tmplitem="277" > blocks in email. */

How To Embed Videos in an HTML Email


It should be noted that nowadays most all webmail clients, like Gmail, it is enough to simply put a YouTube link in the body of the email, and Gmail will render that link as a playable video embedded directly within the body of the email. There are other email clients that do this as well. Another way to embed a video is using the HTML 5 video tag, as shown in the following section. 

Using the HTML 5 Video Tag

Following is a simple example of how to use the HTML 5 video tag that you would place anywhere within the <body> tag of your HTML email. 

(info) Note: this tag only has limited support, in a limited set of mail clients

<video controls=""
type="video/mp4" >


  • Poster – the opening image to display prior to playing the video
  • Src – the URL to the video
  • Type – indicates video format of the video you're using, for example: 
    • video/MP4
    • video/WebM
    • video/Ogg

Currently, there are 3 supported video formats types: MP4, WebM, and Ogg:

Internet ExplorerYESNONO
from Firefox 21
from Firefox 30 for Linux
From Opera 25
  • MP4 = MPEG 4 files with H264 video codec and AAC audio codec
  • WebM = WebM files with VP8 video codec and Vorbis audio codec
  • Ogg = Ogg files with Theora video codec and Vorbis audio codec