Outlook for Mac for Office 365 Categories when importing data

In Outlook for Mac 2011, categories were local to the client.  The category names assigned to items in the mailbox were part of the properties of the items, however the colors associated with the categories were stored only locally on the client.  This means that the category names would roam with the mailbox when accessed on other clients, however the color associated with those categories would not roam, because the categories and colors were not part of the Master Category List.

Outlook for Mac for Office 365 has a new feature so categories and category colors are now synchronized to the Master Category List (MCL) in the mailbox when connected to an Exchange mailbox.  This allows the categories to roam with you between devices and clients.  Users in Outlook for Windows, OWA, and Outlook for Mac for Office 365 are able to view and modify the categories as they prefer in order to assign categories to mail, contact, and calendar items.  The Master Category List will be referred to as the MCL in the remainder of this article.

While utilizing the MCL to store categories is a great feature improvement in Outlook for Mac for Office 365, there are some caveats to be aware of with categories and category colors when you are importing data into Outlook for Mac for Office 365 from a PST or OLM file.

Types of Categories

First, understand that there are three types of categories in Outlook for Mac for Office 365: Master Category List (MCL) categories, local categories, and item only categories.  Here’ a comparison of the 3 types:

MCL Categories Local Categories Item Only categories
Category roaming ability Yes No No
Category storage location In the MCL in the Mailbox on the Exchange server Local to the Outlook client Local to the Outlook client

Category type availability

In Exchange mailbox folders In On My Computer folders and IMAP/POP account folders In the item only after being moved from On My Computer Imported data

Number of colors

25 colors* Thousands of colors N/A

Default category names and colors 


* MCL categories have fewer color choices due to Exchange having a pre-set list of colors that can be utilized for categories, while local categories can be custom selected, thus can be any color.

When importing data into Outlook for Mac for Office 365 from an OLM or PST file, data is imported into local On My Computer folders, then later you can manually move the data to your Exchange mailbox folders if you prefer.  Because the data is imported into On My Computer folders, the categories and colors that were assigned to these items previously are now local categories. 

If you move the items from the On My Computer folder into the Exchange account, the local category becomes an item only category, and the color will be lost.  The items will still have the correct category name assigned to them, but the color will appear to be white.  Item only categories are utilized in this scenario because Outlook does not automatically add a category to the MCL when an item with an assigned local category is moved into the Exchange mailbox.


In Outlook for Mac 2011, you categorized 3 items with custom category names and colors.  In this example, we have 3 emails assigned with 3 different custom categories and custom colors:

You export these emails from Outlook for Mac 2011 and then import them into Outlook for Mac for Office 365.  The emails are imported into your On My Computer folder, and when you view them you see the categories and custom colors are still assigned to them.  These are local categories.

Note: In Outlook for Mac for Office 365, the categories are displayed as color blocks on the right rather than the email sender name and subject being colored like in Outlook for Mac 2011.

From your On My Computer folder, select the three emails and move them into an Exchange Mailbox folder.  The emails will now appear to not have a category assigned unless the email is selected, because the category is white, it does not appear against the white background.  

The category names are still assigned to all the items that you imported, and these categories are now item only categories.  If you click Categorize on the Home Ribbon in your Exchange folder, you do not see the Fuchsia category, and it does not appear under Edit Categories either.

Now the question is: "What do I do with these Item Only Categories?" 

It’s actually quite easy to fix these categories to add them to the MCL, just follow these steps:

  1. With an Exchange folder selected, click Categorize, Edit Categories.  This displays your MCL.
    Note: If you have multiple mail accounts added to Outlook, they will appear here, as each Exchange account has its own separate MCL, and IMAP or POP accounts use their own local categories.
  2. Click the plus sign (+) to add a new category.
  3. Enter the category name EXACTLY as the item only category name.  If it's different or misspelled, this will not work as expected.  In my example, I enter "Fuchsia".  
  4. Then click the color square to the left of the name in order to pick a color for this category.

  5. Repeat steps 1- 4 for each of the categories you want to add to the MCL.
  6. Close the Categories window, and navigate to the items imported that had the Item Only category names assigned, and you will see that they have all been updated properly with the colors you assigned in the MCL.  These are now MCL categories.

If you prefer to remove the Item Only category from items instead of adding it to the MCL, this can be accomplished in one of two ways:

  1. Select the item with the item only category assigned to it.  Click Categorize on the Ribbon, and then click Clear All.
    Note: You can also select multiple emails and use this method to remove all categories from all of the items at once.
  2. Select the item with the item only category assigned to it.  In the Reading Pane, right-click the item only category, and select Remove Category.
    Note: This method is good if you have assigned other categories to the item and you do not want to clear all of the categories.

Comments (7)
  1. Anonymous says:


  2. Anonymous says:


  3. Anonymous says:

    Great article

  4. KellyK says:

    What about custom categories from Outlook 2011 that were imported into Outlook for Mac 365, and do not appear in the MCL but show as white item only categories in the calendar? How can you edit/delete/use those when they do appear in the MCL?

  5. Chris says:

    Yes, I have the same problem as Kelly. I have a number of categories under my "Calendar" section, however no way to edit or delete them?

  6. Chris says:

    Got it, if go into "Mail" then "Categorize" in the top ribbon. Add the categories that you want to remove, making sure that you select the "None" colour option. Then remove the category just added, it removes the older categories.

  7. Geoff Watson says:

    Really nice fix for the abandoned categories I picked up from my Office 2011 into my Office 2016 Outlook client. Very much appreciate the post – that really worked!

Comments are closed.

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