Hello @LKStrubh ,
If the contacts are correct that they're not receiving the emails, the only other way we could report a delivery and open is if their network / email program is "opening" them as part of a security check. I'd recommend asking your affected contacts to check their inboxes and spam folders, and if they're indeed not finding your emails, then you can go through some deliverability troubleshooting.
Here are some general best practices for deliverability. Deliverability can have a lot of variables, from elements on our side, on your side, on the recipient's side, and in their email system company's side. It's also a generally good idea to set up additional authentication for your emails - whether that's through us if you have a free domain (e.g. Gmail, Yahoo, AOL, etc.) or via self-authentication if you have your own domain (such as through a business or other organization).
If you'd like to learn more about safelisting, and what it entails:
Safelisting domains in a security system
Safelisting email addresses in an email client or security system
If you're wanting more in-depth, specialized insight on your current deliverability, it'd be worth speaking with one of our Deliverability agents.
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