Spam filters look at a long list of criteria to judge whether a message should be marked as spam. Here are a few:
- The Junk Mail filter has identified one or more keywords in your email message or subject line that spammers often use in their messages.
- The use of excessive punctuation, all capitals or too many emoticons may affect your email delivery.
- The recipient has flagged the sender as someone that sends spam.
- The recipient's ISP has filtered the mail as spam or junk mail based on the content or the sender's IP address.
- The recipient has set up spam tagging 'rules' in their mail program that are very generic and might tag a lot of mail as spam .