POP3 Clients only download from inbox.

If you set up a exchange 2010 mailbox with Junk E-mail folder enabled, the Junk e-mail will not be downloaded to POP3 clients' Junk e-mail folder. Some users want to look into the Junk e-mail folder for useful messages.

To turn off the Junk e-mail folder:

By OWA:

By EMS:

Set-MailboxJunkEmailConfiguration -Identity Kaiming -Enabled $false

It's better to create a transport rule:

New-TransportRule -Name '[SPAM]' -Comments '' -Priority '0' -Enabled $true -SCLOver '6' -PrependSubject '[SPAM]' -ExceptIfFrom 'Rudy@vanarts.com'