[Gmail] When to use the "Report spam" button?

When to use the "Report spam" button in Gmail?

[tribal]

I can't find it in the Gmail help [mail.google.com] and was wondering about this for a while..

I have a contactform on my website, and i forward the messages of that form to my Gmail address as the sender info@*mywebsite*.com.
When spam messages are sent from that contactform to my gmail address, should i report it as spam?

I don't want to mark the sender(myself) as spam, but i do want to mark the content of some messages as spam.

[duanwenming]

Hi tribal, i think you should better setup some kind of filter in your gmail account, so that you can just archive those email when you receive them, but do'd better find the similarity.