lost email but showed up in spotlight then clicking on it returns nothing

I recently reset up an old iCloud email account I had not used for several years. It goes back almost 20 years. Some emails were missing from a folder. But when I searched for them, they showed up in spotlight (some searches not always). The I clicked on the email in spotlight and it did not show anything. So there is some record of the email somewhere. How do I find it? Not on the iCloud website either. Thanks!