Why are my open rates not accurate?

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How are open rates tracked?

A 1x1 pixel transparent GIF image is inserted in each email and includes a unique reference. When the image is downloaded, an open event is triggered.

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Why are my open rates not accurate?

Open tracking is generally not accurate because each inbox handles incoming email differently.

Clipped messages in Gmail happen when you send a message over 102KB. A message over this size won’t be counted as an open unless the recipient views the entire message. Resend’s Deliverability Insights on the email will note if a message exceeds this threshold.

Some inboxes do not download images by default or block/cache assets with a corporate firewall. This approach can prevent the open event from being tracked.

Other inboxes open the email prior to delivering in order to scan for malware or to protect user privacy. This approach can trigger an open event without the recipient reading your email.

Because of this, open tracking is not a statistically accurate way of detecting if your users are engaging with your content.

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Does open tracking impact inbox placement?

Though open tracking should not impact if your email is delivered, it most likely will impact your inbox placement. Trackers are generally used by marketers and even spammers. Because of this, inbox providers will often use open tracking as a signal that your email is promotional, or even spam, and categorize accordingly.

We suggest disabling open rates for transactional email, to maximize inbox placement.

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What’s the alternative?

Instead of relying on open rates, there are a few other ways to still understand your sending.

1. Track Clicks: Monitoring the link clicks is an even more granular way to know how a recipient engaged with your email. By knowing if they clicked, you also know that they read parts of your email and took action.
2. Track Outside the Inbox: Often emails are sent as a means to an end. Maybe it’s to increase page visits of an announcement or convert free users to paid. Tracking your sending by metrics outside of the inbox can be a great way to understand the true impact of your sending.