To disable the Junk email filter, you can do the following:

1. Open the Preferences for Outlook (command + ,) or go to "Outlook" menu and select Preferences.
2. From "Tools" menu, select Junk Email Protection....

  3.  Set level of junk e-mail protection to None

Important If you configure the Mailing List Manager to process and move messages to other Inbox folders, the junk mail filter will not process these messages.

Note

• Each IMAP (IMAP: A common type of Internet-based mail account such as Gmail, AOL Mail, and many others. Messages from these accounts appear in folders in the Outlook folder list, under the name of the account.) and Office 365 account (Office 365 account: An account managed by Microsoft Exchange Server. Microsoft Exchange accounts are used by organizations with many users. They make it possible to synchronize e-mail, calendars, and contacts between multiple computers.) account has its own Junk E-mail folder. The name of this folder may vary slightly for server-based folders.
• For IMAP accounts, Outlook applies the junk mail filter only to messages received in the Inbox folder. For POP (POP: A common type of Internet-based mail account. Examples are Windows Live Hotmail and Yahoo! Mail. After you add a POP account to Outlook, messages from the account appear in the folder list under On My Computer.) accounts, Outlook applies the junk mail filter to all messages.
• Outlook does not apply the junk mail filter to messages from a Office 365 account (Office 365 account: An account managed by Microsoft Exchange Server. Microsoft Exchange accounts are used by organizations with many users. They make it possible to synchronize e-mail, calendars, and contacts between multiple computers.). For these accounts, junk mail filtering occurs on the Exchange server.