How to parse deeper URL's?

I want to scrape email addresses from an URL called http://domain.net/niche/en/forum/topic/thread

However, it always only scrapes from http://domain.net/niche/en/forum/topic/ and not more deeper. 

But most of the email addresses I intend to target are located in the threads! 

How to set this up?

See the option "How deep to parse this site". You can set a custom level or parse everything, etc.