If you feel you can help to fight spam, please ask for an admin account.
Here are measures to remove spam, in increasing.
isolated spam message
- go to the message, click on "close" or "delete" if someone already closed it.
bunch of spams from the same user
- click on the user's nickname (bottom right of the question) - click on "moderation" (top right) - click on "block user and delete all content"
lot of bunch of spams with a similar pattern
- go to http://ask.sagemath.org/settings/MODERATION/ - add the typical keywords appearing in the spams on the "Reject all posts with these phrases" field.
overloaded, need to stop the flood
- go to http://ask.sagemath.org/settings/ACCESS_CONTROL/ - select "Allow only registered user to access the forum"