When you send a tracked email or a campaign, by default, Propeller will attempt to track whether the recipient opens the email and if they click on any links.
To track email opens, Propeller inserts an invisible image, often referred to as a hidden pixel, which references a unique URL linked to this specific email. If the recipient's email client (i.e. Gmail, Outlook, iPhone Mail, etc.) accesses the image, Propeller considers that email as viewed.
To track link clicks, Propeller rewrites each of the links it finds in the email with a unique link back to Propeller. When the recipient clicks the link, they are routed to Propeller for a split second where the click is logged, then rerouted to the original link.
Both of these techniques are industry standard and used by most of the email products on the market, including Mailchimp, Constant Contact, etc. And in the case of the hidden pixel, they are somewhat unreliable.
One of the most common problems is that a recipient may not have images turned on. Therefore, even though the email might be opened, Propeller never finds out because the email client never accesses the image's URL.
Another problem is that some companies run sensitive malware scanners. These can trigger visits to links in emails automatically and in sometimes high volume if simulating tests from multiple devices, such as iOS, Android, MacOS, and Windows. The result can be many clicks registered with no views.
And initially, you may run into problems when testing this behavior with one of your own email accounts. This is because we try to prevent your views and clicks from counting. So if you click on a test link using the browser that you have logged into Propeller with, the click won't count. And depending on how your email client works, it can prevent email views as well. In addition, we don't track emails send to colleagues at the same domain as you, so no views or clicks will be registered from them either.
To test how view and click tracking works, we generally recommend sending to a personal email address and using your mobile device to access the email (assuming you haven't used the device to log in to Propeller). Second best thing is to send to a friend outside your company.