AM0
How ESP (specifically Outlook) determines an open?
Would anyone be able to give an explanation on how certain ESPs (specifically Outlook) determine an open?
In my example, Email A was sent, the recipient, using Outlook, read through his email, but didn’t click to download the images. The result – was the recipient was not in the open list.
Here's a helpful article I found recently regarding open rates.
http://help.pardot.com/customer/portal/articles/2125897-how-are-html-opens-measured-
Hi Anne! Would you mind clarifying your question a bit? You mention Outlook as an example, however I typically think of Outlook as an "email client" rather than an "ESP." ESP stands for "Email Service Provider" and these are platforms like MailChimp, Constant Contact, Salesforce Marketing Cloud, etc. They manage your list and do the "sending" part on behalf of a company/marketer.
An email client, like Outlook, receives the mail and is responsible for displaying it.
It's a combination of both the email client (such as Outlook) and the ESP (such as MailChimp) that determine how opens are tracked. Most ESPs use a 1x1 tracking pixel to measure opens. At you point out, some email clients (such as Outlook) block images automatically. In the case where an ESP relies on image-based open tracking and images were never enabled, no open would be tracked.
Some ESPs (you'd need to check with yours) will infer an open from a click. For example, if images are turned off and the user doesn't click to download, BUT they do click a link in the email, some ESPs will assume that since a link was clicked, the email must have been opened, and they'll count an open even though images were not turned on. Not all ESPs do this, however. You'd want to check with the ESP that sent the email to see how they track opens.
For this reason it's always important to understand how your ESP tracks all their metrics. In the past when I've switched from one ESP to another (or worked with customers on different ESPs), I've seen many variations on how both opens and clicks are reported, so it's sometimes comparing apples to oranges since the metrics are being tracked differently behind the scenes.