The anti-spam filter prevents your inbox from being saturated with junk mail, and moves these type of messages to a mail folder called SPAM. carries out this classification automatically in Outlook and Outlook Express.
Note: If you have a different email client, you should create this folder manually. Then, a rule should be created so that all messages detected as spam are automatically moved to the Spam folder. Refer to the How to deal with spam in other e-mail clients section for more information.
Nevertheless, on occasions it is possible that the anti-spam filter classifies as spam messages that are not in fact junk mail. For this reason it is advisable to check the Spam folder from time to time. If it contains valid mail, you should reclassify it as Not Spam. By doing this, you will prevent messages with similar characteristics being classified as spam in the future.
If you think that one of the messages in the Spam folder should not be there, follow the instructions below:
In the Outlook or Outlook Express Spam folder, select the message you want to classify as Not Spam.
Click Classify as NOT SPAM 
. When you click this button, the message will be returned to the inbox. From then on, similar messages received will not be classified as spam.
If you have received a junk mail message that has not been moved to the Spam folder automatically, you can classify it as spam as follows:
In the Outlook or Outlook Express inbox, select the message you want to classify as spam.
Click Classify as SPAM 
. This will move the message to the Outlook Spam folder. So, the next time a mail message with these characteristics is detected, it will be classified as spam automatically.
When an email message is classified as Not Spam by clicking tthe relevant button, a dialog box will be displayed which will allow you to add its senders to the list of trusted senders. By doing this, other messages sent by the same sender will no longer be classified as spam in the future.