Waitforelementnotpresent locator

I’m trying to automate something with incoming e-mails in gmail. So I want to wait until a new e-mail arrives and then automatically click on it. I’m using the waitforelementnotpresent command. As target I tried to select the line with “no unread e-mail”. But as the id changes sometimes after reloading it fails. Is it possible to select the name as target with the name locator?
If yes, what do I have exactly to fill in in the field target? name = no unread e-mails?

Some ideas:

About changing IDs: Waitforelementnotpresent locator

See also waitForPageToLoad doesn't wait

Or use computer vision instead: If {picture} then {do this}