How to use MS Outlook rules to filter internal emails from external trusted, and untrusted mails

My job title is a magnet for spam, and the predictable format of email addresses across companies means I have to work my way through a load of targeted spam everyday.

Spam filters do a great job, but targeted spam is difficult to identify, as it’s sent person to person, it’s just unwanted direct e-mail.

I recently took some time to setup some rules in MS Outlook, and this has made a massive difference, so thought I’d share this approach, in-case it helps others…

The Aim

To prevent me from auto-ignoring mail, I highlight mail from External Trusted Senders, and External Untrusted Senders, so I can look at these separately.

The Approach

I setup categories for External Trusted Senders, and External Untrusted Senders. The inbox view automatically highlights these as such, so they are easy to ignore day-to-day (I prefer this to auto-deleting them, as there’s always the odd new sender I haven’t added to my trusted list).

I then use a search folder to separately view the External Untrusted Sender emails. I quickly look through this folder every week to spot any external senders I need to add to my trusted list, I just select the rest of the emails and delete them in one go! At this point, I feel quite smug!


You are likely to need to edit the Trusted party rule regularly initially, while you identify a list of domain names that you trust. I now have this working with a list of all our suppliers and trusted partners, and find it a huge help in the fight against targeted spam.

Please leave comments if this is helpful, as it’s great to know if my effort was worth it!


I'm passionate about technology, and particularly helping people make the most of it. I've spent the last 30 years helping others make the most of technology. My career started in IBM, but I choose to move into smaller business environments, to use a breadth of skills, and help businesses step change their IT services. My skills range from user based technology, through business systems (applications) to infrastructure. I also have a long background in IT security. I focus on what I consider to be "productive technology", i.e. adding genuine value to peoples lives. I'm not a big gamer, and don't hold much interest in what I consider to be disposable consumer technologies. During the day, you'll find me consulting with businesses or heading up an IT department. At the weekend, you'll find me sat at my Linux PC, writing PHP or Python code, or trying to help others on Twitter, this blog, or my YouTube channel: Artexic.