Note: this tip assumes that the email in question is being moved after receipt, that is, the email first appears in your email inbox, then gets moved to your junk folder. If instead you're trying to prevent received email from being immediately labelled as spam ("false-positive"), then instead please refer to white-listing instructions in our knowledgebase article on using the advanced anti-spam and virus system. Else read on...
The most common cause of this behavior (email mysteriously moved to Junk folder after receipt) is that a local email client, such as your Outlook, Mac Mail, or even smart phone, is identifying the mail as spam for one reason or another. Often, resolving this issue is as straight-forward as adding the sender's email address to your address book, so your local email client recognizes it as a valid sender, not spam.
