There’s several spam checks of incoming email, which one is working for you.
As we’ve mentioned before in Office-Watch.com, there’s usually more than one anti-spam filter on incoming messages. If those filter don’t work or are too aggressive you might miss out of messages you want to see.
Typically an email is sent to your ISP or other mail host (hosted Exchange, Hotmail/Outlook.com, Gmail etc). Before messages are delivered to your online mailbox there’s almost certainly some anti-spam filter in place.
Occasionally some ISP support staff might say there’s no spam filter on their mail, but that highly unlikely these days.
Sometimes there’s multiple anti-spam traps just to keep up with the massive amount of incoming messages. There’s a first level of defense that quickly deletes the really obvious spam. A second anti-spam filter then analyses the incoming emails in more detail to remove yet more spam.
Microsoft’s Exchange Server gives each incoming message a Spam Confidence Level (SCL) number. The higher the SCL, the more likely it is to be spam. High scoring emails are usually deleted or quarantined so end-users never see them. Low ranking SCL’s (which may or may not be spam) can be either sent to the users Inbox (for Outlook to check) or placed directly in the Junk Email folder so users can check through the messages for any ‘false positives’ (i.e. messages that were wrong considered spam).
Problem is, no spam filter is perfect. Messages that look like spam to a machine might well be emails you’re waiting for. Emailed order confirmations of online purchases are just one example of messages that spam filters have trouble dealing with.
In addition, these online spam filters don’t have the personal settings you’ve put into Outlook like Safe Senders and Safe Recipients.
For Outlook users the final spam filter is in Outlook itself. Microsoft downloads updates to the Junk Email filter so Outlook can cope with new types of spam.
How can you tell which spam filter has put a message into your Junk Email folder?
Click on a message in the Junk Email folder, buried in the notes at the top is a line
“This message was marked as spam using the Outlook Junk E-mail filter”
“This message was marked as spam using a junk filter other than the Outlook Junk E-mail filter”
This applies to Outlook 2013, Outlook 2010 and Outlook 2007 SP2 or later.