Search related to a date in the Expires: header

Hi everyone,

I posted a feature request about the use of the email Expires: header in Evolution : Manage Email Expiration Dates in Gnome Evolution (#2997) · Issues · GNOME / evolution · GitLab

But it looks like it’s already possible to search on the header of an email.

Could you give me an example of a “Free Form Expression” that would allow me to search for “All dates in the past for the Expires: header”? I’ve done several tests but unfortunately haven’t been successful.

Thank you very much