When you open a reply that someone sent you, Mailsuite may sometimes register this as an "open" from that recipient, even though you were the one viewing the message. This can make it look like the recipient opened the email multiple times when in fact you were the one reading it.
Mailsuite has a mechanism that can detect when you open a sent email yourself, and ignore that open, but this only works if you are viewing the email on a computer browser that has the Mailsuite browser extension installed or on the Mailsuite mobile app for Android and iOS. If you open the reply on a different device, browser, or Google account that does not have the extension installed, Mailsuite has no way to recognize that it's you opening it, so the open can be mistakenly attributed to the recipient.
To avoid this, make sure you open sent mails and replies using a browser where the Mailsuite extension is installed and active or the Mailsuite mobile app.