Why did my test email go to spam?

Spam filters look at a long list of criteria to judge whether a message should be marked as spam. Here are a few:

1. The Junk Mail filter has identified one or more keywords  in your email message or subject line that spammers often use in their messages.  
2. The use of excessive punctuation, all capitals or too many emoticons may affect your email delivery.
3. The recipient has flagged the sender as someone that sends spam.
4. The recipient's ISP has filtered the mail as spam or junk mail based on the content or the sender's IP address.
5. 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 .