Microsoft Graph API Outlook Inbox filter sender/emailAddress/address does not return expected response

Question

When I am trying to filter emails in my inbox using the following Python code snippet,

sender_email = '[email protected]'
filter_expression = f"sender/emailAddress/address eq '{sender_email}'"
url = f"https://graph.microsoft.com/v1.0/users/{user_principal_name}/mailFolders/Inbox/messages?$filter={filter_expression}&top=1000"

I receive the following empty response

{
    "@odata.context": "https://graph.microsoft.com/v1.0/$metadata#users('abc%40test.de')/mailFolders('Inbox')/messages",
    "value": []
}

But if I read all mails without filtering, I receive the correct result:

...
    "subject": "Scanned images", 
...
    "sender": {
        "emailAddress": {
            "name": "Test User",
            "address": "[email protected]"
        }
    },
    "from": {
        "emailAddress": {
            "name": "Test User",
            "address": "[email protected]"
        }
    },
...

Interestingly if I use a filter for the subject, I receive the correct result email

filter_expression = f"startswith(subject, 'Scanned')"

Here is the code I use for sending the request

def graph_get(url, token):
    headers = {"Authorization": f"Bearer {token}"}
    r = requests.get(url, headers=headers)
    return r.json()

response = graph_get(url, token)

What am I doing wrong with my sender/emailAddress/address filter? Any ideas?

Answer 1

In some cases, filtering sender/emailAddress/address with eq operator might not work. As an alternative, you can filter it with startsWith operator by modifying your code like this:

filter_expression = f"startsWith(from/emailAddress/address,'{sender_email}')"

I registered one Azure AD application and granted Mail.Read permission of Application type as below:

Now, I generated access token using client credentials flow via Postman with below parameters:

POST https://login.microsoftonline.com/tenantId/oauth2/v2.0/token
grant_type:client_credentials
client_id: appId
client_secret: secret 
scope: https://graph.microsoft.com/.default

Response:

When I ran below python code by modifying the filter expression and including above token, I got the results successfully as below:

import requests

sender_email = '[email protected]'
filter_expression = f"startsWith(from/emailAddress/address,'{sender_email}')"
user_principal_name = '[email protected]'
token = 'paste_token_here'

url = f"https://graph.microsoft.com/v1.0/users/{user_principal_name}/mailFolders/Inbox/messages?$filter={filter_expression}&top=1000"

def graph_get(url, token):
    headers = {"Authorization": f"Bearer {token}"}
    r = requests.get(url, headers=headers)
    print(r.json())

response = graph_get(url, token)

Response: