Is there a way to scrape email addresses from pages with unknown source code patterns?

Not sure if my question is clear...

But the scrapper works very well when every page has the same format, same elements, but what if you are scrapping different pages of different websites?

The css classes, all will be different on every site, are there any kind of wild cards * or techniques for this?

Maybe if|and|or conditions?

No, unfortunately, each site with different structure will need a new sitemap.