Overview
Open tracking shows you when a prospect opened your email, so you can follow up at the right moment and prioritize engaged leads. Open tracking helps you gauge interest, time your outreach, and spot which messages are getting attention, even if the prospect hasn’t replied yet.
When you enable open tracking, Apollo adds a tiny 1-pixel image called a tracking pixel to your emails. When a prospect opens the email and the image loads, Apollo logs an open event and attributes it to the specific prospect and message.
You should only enable open tracking if you have a strong domain reputation and understand email deliverability best practices. To minimize risk, Apollo recommends using tracking strategically — for specific time-bound tests or campaigns. Once you’ve gathered the insights you need, turn off tracking to help protect your domain reputation.
Check out the following sections to learn more and use open tracking.
Open tracking is available on select Apollo plans. If you need to use open tracking, upgrade your plan. If you have questions about upgrading, reach out to the Apollo sales team.
Enable Open Tracking
Before you use open tracking, Apollo strongly recommends that you set up a custom tracking subdomain. If you haven't, or can't use a tracking subdomain, you should turn off both open and click tracking to protect your domain reputation.
To enable open tracking:
- Launch Apollo and go to Settings > Profile > Email settings.
- Check Enable open tracking.
You have now enabled open tracking.
Open tracking is enabled per user in Apollo. If you want your whole team to use it, each person needs to turn it on in their own settings.
Check out answers to some frequently asked questions about open tracking, or explore next steps to keep up the momentum.
Apollo's tracking pixel is hosted on Heroku, so it appears as a Heroku URL in the email's HTML.
To deactivate open tracking, return to Email settings, and uncheck Enable open tracking.
FAQs
| Frequently asked questions | ||
|---|---|---|
| What’s the difference between open tracking and click tracking? | Can Apollo filter out opens I trigger myself? | Why does Apollo say an email was opened when I’m pretty sure it wasn’t? |
| Should I use open tracking for every email I send? | How do I report on the number of emails opened? | Why is my open rate so low, even though I know people are seeing my emails? |
What’s the difference between open tracking and click tracking?
Click tracking tells you when someone clicks a link in your email. Open tracking shows you when your email was opened. Clicks are usually a stronger signal of interest, but both are helpful for understanding engagement in time-bound campaigns or A/B tests.
Can Apollo filter out opens I trigger myself?
In many instances, Apollo will detect when you open your own engagement messages and exclude these opens during tracking. However, there are some scenarios when Apollo might still track your self-opens as an open event.
| When Apollo can detect and exclude self-opens | The Apollo Chrome Extension can detect self-opens and ensure they aren't counted. The connection between the extension and your Gmail account helps Apollo recognize and exclude self-opens. |
|---|---|
| If you haven't installed the Apollo Chrome Extension, Apollo checks the network IP address of the message opener and compares it with the sender's most recent IP address. When these match, Apollo recognizes the event as a self-open and doesn't track it. Interactions with unsubscribe links and tracking links are intelligently excluded in the same way as opens. When Apollo detects that the unsubscriber and email sender have the same network IP address, Apollo automatically excludes the unsubscribe link in the sent message. IP Address Settings
For security purposes, if Apollo can't read your network's IP address then it can't reliably exclude your self-opens. If you need to track self-opens in Outlook, contact your ISP or network administrator to switch your connection from IPv6 to IPv4. |
|
| When Apollo can't detect and exclude self-opens | Apollo can't detect self-opens if you open one of your emails on a different device than the one you used to send it from. If you send a message from your work laptop and open the same message on your mobile phone, Apollo won't recognize that you've opened your own email. |
Why does Apollo say an email was opened when I’m pretty sure it wasn’t?
With open tracking, you can experience bot opens. When you send an email to an inbox, anti-virus or security scanning bots often open the email to ensure there's nothing harmful in it. Mailbox providers may also prefetch text or images to ensure emails load faster when the recipient views them. These events can inflate your campaign metrics, making it appear that you have a higher open rate than you really do. Apollo allows you to include or exclude bot opens when you report on sequences and emails.
Should I use open tracking for every email I send?
Not always. While open tracking can help you understand engagement and time your follow-ups, using it on every email can increase the chances of spam filtering, especially if your domain reputation isn’t strong. Apollo recommends using open tracking selectively, such as for short-term tests or specific outbound campaigns where you’re measuring performance. Once you’ve gathered the insights you need, it’s a good idea to turn it off to protect deliverability.
How do I report on the number of emails opened?
You can track open activity from several areas in Apollo:
| Reports | Navigate to Analytics > Reports. You can use reports built by Apollo, including the email engagement dashboard, email stats report, email activity by week report, or most effective email sequences report.
Alternatively, click to create a custom report to show total opens, open rates, and choose whether to include or exclude bot opens. Filter by sequence, team, or user. |
|---|---|
| Emails | Navigate to Emails to filter for opened emails, number of opens, or last opened date range. |
| Sequences | Navigate to Sequences and click into a specific sequence to see statistics including open rate per individual. Click Report to see total opens, open rates, and engagement trends over time. |
To learn more, check out Report on Sequences.
Why is my open rate so low, even though I know people are seeing my emails?
Low open rates are usually caused by poor email deliverability or gaps in how opens are tracked. If your domain has a weak reputation, some providers may mark your emails as spam, even if they technically show as “delivered.” When that happens, your message never reaches the inbox, and your contact never sees or opens it. That results in low open rates.
False negatives are also possible. This happens when a contact opens your email but their email client blocks images, preventing the tracking pixel from loading. Some users have images disabled by default, which means Apollo can't log the open event even if the email was read.
To avoid both issues, follow email deliverability best practices, set up a custom tracking subdomain, and always include a clickable link in your emails. If someone clicks, you can be confident they saw your message—even if the open wasn’t tracked.
Next Steps
Keep up the momentum with these next steps:
| Email Deliverability Best Practices | Learn how to improve deliverability, avoid spam folders, and increase response rates. Apollo's guide covers domain setup, sending behavior, and writing emails that sound human and authentic. |
|---|---|
| Set Up a Custom Tracking Subdomain | Improve tracking accuracy and protect your sender reputation by setting up a branded subdomain. |
| Use Click Tracking | Monitor how recipients engage with your links with click tracking on Apollo. |
| Email Tracking Overview | Learn how Apollo tracks opens and clicks and how to interpret your email engagement data. |
| Use an A/B Test in a Sequence | Run A/B tests in your sequences to compare subject lines, messaging, or timing. Use the results alongside open and click rates to find out what drives engagement. |