How do I add a column to the new Outlook (Category/Size) to allow email to be organized by those fields.

Hi @Nuno Godinho, 

Thank you for reaching out to the Microsoft Q&A forum. 

Based on your description, you are unable to add columns such as Category or Size in the new Outlook to organize your email, and you have not found a "Show Columns" option. We truly appreciate the time and effort you have invested in managing this issue, especially since it has been outstanding for an extended period. 

This situation arises because the new Outlook for Windows currently does not support adding or customizing columns like Category or Size in the message list. The classic Outlook interface included these customization options, but the new version prioritizes a streamlined design and has yet to implement this level of column customization. This limitation is well recognized, and Microsoft is continuously working on enhancing the new Outlook experience. Feature comparison between new Outlook and classic Outlook - Microsoft Support 

To address this issue in a way that suits your situation, please follow these steps: 

• Check if there is an option in your Outlook interface to switch back to the classic (old) Outlook. This is often found as a toggle in the upper right corner. 
• If available, use this option to revert to the classic Outlook, where you can add columns via View > View Settings > Columns, and include Category and Size for your folders. Add or remove columns in the Inbox - Microsoft Support 
• If you choose to remain on the new Outlook, you can manage categories by right-clicking emails and selecting Categorize for color-coding, though column-based sorting is not currently available. 

• In the Settings > Mail, you can also explore "Conditional Formatting".  Add a new rule to highlight or change the font color for messages where "To" contains data. 

Considering the importance of this feature for your workflow, reverting to the classic Outlook is a recommended approach until these customization features become available in the new Outlook.  

Alternatively, as a forum moderator, I hope you understand that I don’t have the ability to modify or escalate product issues directly. However, I strongly recommend submitting your feedback through the Outlook · Community. This is the most effective way to ensure your voice reaches the product team and can be considered about how company-only contacts are handled in search results, with potential improvements being considered  for future improvements. 

You've clearly identified a real-world challenge, and your suggestion reflects a deep understanding of user needs - feedback like yours is truly valuable and helps shape the future of Microsoft team.    

Sharing your experience through this channel is one of the most effective ways to advocate for improvements that benefit both you and the broader community.   

Once you’ve submitted your feedback, feel free to share the link here. I’d be happy to upvote it to help increase its visibility.     

Additionally, many users have raised similar concerns but may not know where to provide feedback. If my response has helped clarify the situation and guide you toward a next step, please consider marking it as the “Accepted Answer.” Doing so will pin this post to the top, making it easier for others facing the same issue to find and support your feedback.  

Thank you again for being part of the Microsoft Q&A community. If you have any further questions or updates, feel free to reply here. I’ll be happy to assist further.   

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