Here are the instructions on how to use GMail filters:
1. First, sign in to your GMail account
2. Click on the Settings button that is located in the upper right corner of the GMail page (looks like a screw ) and there select Settings
3. Click on the Filters and Blocked Addresses tab
4. Click on Create a new filter
5. Type a sender's e-mail address in the "From" box and click on Create filter with this search located in the bottom right corner
6. Now you can decide what to do with those e-mails. To have them deleted, check these 3 check-boxes:
- Skip the Inbox (Archive it)
- Delete it
- Never mark it as important
7. If you want to delete current e-mails from that sender, you can check the " Also apply filter to matching conversations" check-box at the top. If not, only the new e-mails will be deleted. When done, click Create filter button
New e-mails from that sender will be automatically deleted.
Let me know if you could follow my instructions.