In this Article I want to show you how to filter no category email in outlook via Power Automate.

In current Outlook 365 connector, there is no option to filter out emails with/without categories.

When I tried to build the flow, I thought I could use Get emails (V3). After I tried I realised that there is no info in the body, but it doesn’t have the categories information, and the most important thing is it may consume more API if I use it first.

Below is an example of one message structure from Get emails (V3) output body value.

            {
                "id": "value",
                "receivedDateTime": "",
                "hasAttachments": false,
                "internetMessageId": "",
                "subject": "",
                "bodyPreview": "Hi...",
                "importance": "normal",
                "conversationId": "",
                "isRead": false,
                "isHtml": true,
                "body": "html body",
                "from": "",
                "toRecipients": "",
                "attachments": []
            },

After check each actions, one option can be used is Send an HTTP request within Outlook 365 connector.combine with Get emails (V3)

Use Send an HTTP request

This action construct a Microsoft Graph REST API request to invoke. These segments are supported:

  1. 1st segment: /me, /users/
  2. 2nd segment: messages, mailFolders, events, calendar, calendars, outlook, inferenceClassification

https://graph.microsoft.com/v1.0/me/messages will be the way to go. But I only want to check my inbox and unread messages.

https://graph.microsoft.com/v1.0/me/mailFolders/Inbox/messages/{messageID} will be perfect for me.

For demonstrate purpose，pseudocode as below：

optional, get emails V3
Send an request to query inbox message and apply to unread message.
Filter if any uncategorized message.
For each message found, assign category.

What won’t work:

  1. Use Odata filter
    filter=categories eq null //not work
filter=categories in //not work
filter=categories/any(c:c eq '')//not work
filter=categories/any(c:c eq null)//not work
filter=categories/any(c:c eq 'null')//not work
filter=categories/any(c:c eq '')//not work
filter=not categories/any() //only work with /me/messages without messgeid varible of course, if purely filter message box only it will work.
  2. Use condition
    equals(item()?['categories'], null) //not work.
equals(length(item()?['categories']), 0)) //nope

Does WORK.

empty(item()?['categories'])
//Returns true if the object, array, or string is empty.

Yes, this is the right one for this scenario.

Flow overview.

Flow break down:

  1. Initialize variable for OData query
    {
  "type": "InitializeVariable",
  "inputs": {
    "variables": [
      {
        "name": "MyQuery",
        "type": "string",
        "value": "filter=isRead eq false&$select=categories&$top=10"
      }
    ]
  },
  "runAfter": {}
}
  2. Send an HTTP request
    {
  "type": "OpenApiConnection",
  "inputs": {
    "parameters": {
      "Uri": "https://graph.microsoft.com/v1.0/me/mailFolders/Inbox/messages?$@{variables('MyQuery')}",
      "Method": "GET",
      "ContentType": "application/json"
    },
    "host": {
      "apiId": "/providers/Microsoft.PowerApps/apis/shared_office365",
      "connection": "shared_office365",
      "operationId": "HttpRequest"
    }
  },
  "runAfter": {
    "Initialize_variable_for_OData_query": [
      "Succeeded"
    ]
  }
}
  3. Filter array only uncategorized message
    {
  "type": "Query",
  "inputs": {
    "from": "@body('Send_an_HTTP_request')?['value']",
    "where": "@empty(item()?['categories'])"
  },
  "runAfter": {
    "Send_an_HTTP_request": [
      "Succeeded"
    ]
  }
}
  4. For each uncategorized message
    {
  "type": "Foreach",
  "foreach": "@outputs('Filter_array_only_uncategorized_message')['body']",
  "actions": {
    "Assigns_an_Outlook_category": {
      "type": "OpenApiConnection",
      "inputs": {
        "parameters": {
          "messageId": "@items('For_each_uncategorized_message')?['id']",
          "category": "FollowUP" //Your category name.
        },
        "host": {
          "apiId": "/providers/Microsoft.PowerApps/apis/shared_office365",
          "connection": "shared_office365",
          "operationId": "AssignCategory"
        }
      }
    }
  },
  "runAfter": {
    "Filter_array_only_uncategorized_message": [
      "Succeeded"
    ]
  }
}
  5. Assigns an Outlook category
    {
  "type": "OpenApiConnection",
  "inputs": {
    "parameters": {
      "messageId": "@items('For_each_uncategorized_message')?['id']",
      "category": "FollowUP"
    },
    "host": {
      "apiId": "/providers/Microsoft.PowerApps/apis/shared_office365",
      "connection": "shared_office365",
      "operationId": "AssignCategory"
    }
  }
}

Compare another one I created before which consume more API.

FilterNonCategoryEmail

Note: The examples shown use only generic and safe identifiers. Always review your own flow exports for sensitive info before sharing publicly.

Enjoy.