https://www.oberlo.com/blog/email-tracker
By installing an email tracker, you’ll be able to learn when your emails were opened, how many times and the location recipients were at when they opened it.
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https://proton.me/support/it/email-tracker-protection
Proton Mail can block spy pixels and tracking links so you can view the full content of your emails without being tracked.
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https://snov.io/email-tracker
Free email tracking extension for Gmail lets you track email opens & clicks, schedule emails, and get engagement reports. No labels, no logos, no paid...
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