How do I save all my contest and award emails as proof for my college application?

Hi everyone, I’m a high school junior applying to colleges next year, and I’ve been doing USACO for two years, moving from Bronze to Gold and joining a few other contests along the way. My counselor suggested I start collecting proof of my achievements, but everything is scattered across my inbox, including result emails, promotion notices, camp invitations and certificate attachments. Screenshots and forwarding don’t look official, and printing each email to PDF one by one takes too long and leaves out the attachments. I also use a school-managed Google account that could be deactivated at some point. What’s the best way to bulk-save only the relevant emails as clean PDFs, keeping the sender, date and attachments intact, and has anyone here used these records for applications or scholarship verification?