Junk Mail in Outlook for Mac 2011: How are they Filtered?

Published on June 8, 2015


The junk mail filtering technique of MS Outlook is quite different. It works according to the mailing protocol used by the application: IMAP, POP3, or MAPI (Exchange Server). In the later segment, we will discuss the filtering criteria used by Outlook to safeguard user account from spam mails.

On Connection with Exchange Server:

It will be interesting to know that when Outlook 2011 for Mac is configured with Exchange Server, it actually does not perform filtering. This job is performed by MS Exchange Server. Emails are scanned at server level and marked junk according to the settings done.

Outlook 2011 14.3.1 and the older versions had the option for Junk mail and senders blocking. This was made available under the junk ribbon and there was facility for customizing the settings. However, on connecting with Exchange Server, these options could be blocked by users owning to the advance server role architecture.

Note: If an outdated Outlook 2011 is used, it is recommended to install all latest fixes and features. To get the updates, click on the "Help" button and then choose "Check for Updates".

However, if Outlook Mac 2011 14.3.2 or later edition is in use, then it should be noted that some hunk filtering features, particularly for Exchange server connection are made.

Outlook 2011 14.3.2 and Exchange 2013:

The Junk E-mail Protection… feature is deactivated. An SMTP address can be added to the list of Blocked senders and to do that, follow the steps shared below:

  • In the Home ribbon, select Junk, and then click Block Sender. This will add the SMTP addresses to the blocked senders list of Exchange Server. After this, all emails that arrive from this SMTP address will be considered Junk and will be moved to the Junk E-mail folder of Outlook.
  • If you are not able to customize the blocked senders list through Outlook 2011, then Outlook Web App can be used as an alternative.

Outlook 2011 14.3.2 and Exchange 2007/2010:

In this case, local senders can be blocked. For this, select the email whose sender has to be blocked, click on the Junk button on the Home ribbon. Now, click on Block Sender or choose Junk E-mail Protection. This will allow to manually add an email address to the list of blocked senders.

Note: The blocked senders list created will be workable for the client (Outlook 2011) only. The blocked senders will not get synced with the server but its affect will take place only when emails arrive to Outlook 2011 that have blocked senders list defined.

On Connection with POP or IMAP:

In this configuration, you have option to utilize the built-in mail filtering capabilities. For customizing the spam mail filtering settings, go to Junk E-mail Protection… option that is available under the Home ribbon. This gives the provision of defining the protection level as None, Low, High, or Exclusive and will also give option for defining Safe Domains or Blocked senders.

Either the mails can be marked Junk or its senders can be blocked. For this, select the message or click on the Junk button and choose Mark as Junk or Block Sender.

  • If the email is marked Junk, then it will be moved to the Junk mail folder but next time if the mail arrives from the same sender, it will arrive to the inbox.
  • If the email sender is blocked, the email will stay in the inbox only but next time when the sender sends a mail, it will be moved to junk folder.

This was a small introduction to what efforts are being done at the client's end to protect the mailbox against spam. More than this, applications are built in with techniques (like Bayesian calculation) that help to catch the spam, depending upon the nature of the emails.