Why are my emails being marked as read without me opening them?

Check your email server settings
Make sure there are no server settings causing emails to be marked as read before opening them.
Check the options within your email application for automatically marked emails as read settings
This may be causing your emails to be marked as read without you seeing them.
Check if a script is running on your server
A script could be set up to open emails automatically, causing them to be marked as read without you seeing them.
Check the source of your emails
If your emails are coming from external sources, they may be marked as read when received for security purposes.