Problem with spam filter on my macbook air mail app

Question

My spam filter just stopped working one day- lots of messages getting through.  I tried monkeying around with the preferences but have not seen any results.  I don't actually know what all the setting s mean so I have probably messed it up good.  Please- which settings should I have it set on to block obvious spam and "learn" what else I consider spam.  Thanks.

Answer 1

Launch the Console application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad. Click Utilities, then Console in the icon grid.
Step 1
Make sure the title of the Console window is All Messages. If it isn't, select All Messages from the SYSTEM LOG QUERIES menu on the left.
Enter the name of the crashed application or process in the Filter text field. Select the messages from the time of the last crash, if any. Copy them (command-C) to the Clipboard. Paste (command-V) into a reply to this message. 
When posting a log extract, be selective. In most cases, a few dozen lines are more than enough.
Please do not indiscriminately dump thousands of lines from the log into this discussion.
Important: Some private information, such as your name, may appear in the log. Anonymize before posting.
Step 2
Still in the Console window, look under User Diagnostic Reports for crash reports related to the process. The report name starts with the name of the crashed process, and ends with ".crash". Select the most recent report and post the entire contents — again, the text, not a screenshot. In the interest of privacy, I suggest that, before posting, you edit out the “Anonymous UUID,” a long string of letters, numbers, and dashes in the header of the report, if it’s present (it may not be.) Please don’t post shutdownStall, spin, or hang logs — they're very long and not helpful.