Past meeting participants

Zoom does not show the user's IP address which can easily be changed via a VPN.

Are you having +1000 meetings per day or +1000 participants in meetings per day?

You could force registration which requires an email address. You could ask participants to rename their device in Zoom to their proper name. You could require participants to have a Zoom account (which is free) and signin before joining the meeting.

If this works please click accept as a solution.

If you want to know for sure who is joining the meeting you can require registration which will ensure participants are tied to a registrant id. You can then compare participant reports to registration reports to consistently obtain emails and first and last name based on registration rather than display name. If you want to automate this there is a Zoom app, Salepager, that lets you generate combined registration and participant reports for meetings with registration letting you assess the quality.