Do some legitimate emails that you receive end up on your spam folder? You may be able to prevent this from happening by putting the sender’s email address on your email server’s allow list. Before we talk about how to do that, let’s start by reviewing the general process of how emails get identified as spam.

When somebody sends an email to you, that email is delivered to your email server and then to your Mac. When your mail server receives the email message it evaluates the message on a dozen or more criteria to assess the likelihood that the email is spam. The email is assigned a score. If the score is high enough then the server will be confident that the message is spam and it may simply delete the message altogether. If the score is lower than the message might be spam, but the server isn’t certain so it’ll mark it as spam and deliver the message to your Spam folder. When the score is lower still then the message will be delivered to your Inbox.

After all of this, your Mac will receive the email, either in your Inbox or Spam folder. If the message comes into your Inbox then your own email application’s spam filtering system could be used to evaluate the message a second time. However, the spam filtering capabilities of common email applications of Apple’s Mail and Microsoft’s Outlook are very limited. In my opinion, they are next to useless. The mail server’s spam filtering system is the system that we need to adjust if legitimate emails are landing in your Spam folder.

Most mail server let you customize your spam filtering system. If your server permits this, then you want to figure out how to add an email address to your allow list. Allow lists are also called safe lists or whitelists. These are lists of individual email addresses, like or domain names, like apple.com, which you trust. Spam filtering systems will review the information you’ve added to your allow list and factor this into its evaluation of likelihood that a message is spam. I’m oversimplifying a bit, but if you add a person’s email address to your allow list then messages from this person will be trusted and will be delivered to your Inbox.

The exact process for adding an email address or a domain name to your allow list varies from mail server to server. Please contact your email hosting company’s support team to get instructions on how to edit your allow list. If Rackspace is your email hosting company then you can follow these instructions for editing your Rackspace whitelist. Many email hosting companies use a system named cPanel. Most cPanel systems use SpamAssassin as their email filtering system. Here are instructions for editing a cPanel SpamAssassin whitelist.

Nobody knows exactly what percentage of all emails sent are spam but I’ve read articles that indicate that between 50-70% of all emails are spam. Spam filtering systems aren’t perfect, but they are highly accurate. While it can be frustrating when a legitimate email message is put into your spam folder, I’m frankly surprised that it doesn’t happen more often considering how many spam messages need to be identified and removed from your Inbox.