How email client recognition works

Updated on 20-October-2016 at 10:16 AM

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To measure open rates for email campaigns sent using the system, a small image is attached to every email sent. This image is only one pixel, and is attached at the bottom of the email, so the recipient does not see this image.

When an email recipient clicks and opens an email, the one pixel image is downloaded from the server. Once this image is downloaded, the system then counts this action as a new “open”.

Note: For security reasons, many email clients disable image downloading by default. These email clients include Outlook 2007, 2010, Gmail, Hotmail, and others.

These restrictions affect the email campaign report statistics.

The percentages shown in the Email Clients graph are based on the recipients that downloaded the one pixel image, and the user-agent (email client) being identified.

If the recipient did not download the image, the system automatically removes this recipient from the calculations. If the recipients user agent cannot be identified, these recipients are added to the "Others" segment from the graph.

For this reason, you may see a smaller number of subscribers using these email clients, although they are actually opening your emails.

On the other hand, some email apps such as iPhone/iPad Mail - load images by default when an email is opened.

Therefore reports on these email clients give you a more precise count of your iPhone subscribers compared to subscribers using other email programs.


How to use the email client report

When you design an email campaign, have in mind what most of your subscribers use to open your emails so that you can optimize different elements of the email content:

  • Subject lines (based on the default length of different email clients),
  • Some HTML tags that may not be rendered under specific email clients (Example: Yahoo - doesn't render <p> correctly), hence the display may be different
  • The layout rendering may differ on from one screen type size to another.

Ensure that you test your email on different email clients before sending a campaign.