Howto set up postfix / amavis to reject mails with non-valid SPF?

Hey there!

I installed mail stack using easyengine.

Now I wanted to add spf check to incoming emails check and have postfix reject emails without valid SPF.

Can I simply follow this tutorial or is there anything I need to consider because of the amavis thingie? https://help.ubuntu.com/community/Postfix/SPF

Thanks!