Some subscribers with strict security settings, such as those using .edu or .gov domains, might generate automatic opens or clicks when you email them. This occurs because spam filters preload links and images to ensure their safety. You can verify this by adding a hidden link in one of your email campaigns and seeing if it gets clicked.
If your audience frequently uses strict domains (such as .edu, .gov, etc.), we recommend asking them to provide their personal email addresses when they subscribe for newsletter/email campaign. If you use online forms to collect subscribers, you could add text suggesting that subscribers use their personal email addresses instead of their business email addresses.