emails suddenly disappeared

Hello dhiyajana,

We're glad you thought to ask Apple Support Communities about the issue you're having with your email no longer appearing after installing iOS 15. Complete the following steps, testing after each one to see if the issue resolves:

• Quit the Mail app, and restart your iPhone as restarting can resolve many odd issues:
  • Close an app on your iPhone or iPod touch
  • Restart your iPhone
• If the behavior continues, remove your email accounts and add them back one at a time, testing after each addition:
  • Those steps are found under "Remove your email account and set it up again" here: If you can't receive email on your iPhone, iPad, or iPod touch
  • For iCloud, tap Settings > [your name] > iCloud, then turn Mail off. Wait a few seconds and turn it back on. Those steps and other helpful tips are found here: If iCloud Mail isn't working
• If you're still having an issue, uninstall the Mail app and reinstall it: Remove apps from iPhone

Let us know how it goes.

Take care.