Email search issue with IdType="ImmutableId"

Kanishka Hewapathirana 20 Reputation points

Hi guys,

We found a problem related to email search. On this week, suddenly found that this functionality is not working now. This functionality worked quite fine on our application without any problem.

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But after remove this Prefer : IdType="ImmutableId, then it is working fine. But not recommended approach right now. I just want to confirm that any changes has been done on Microsoft side. We have not done any changes to the system

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We found our clients are escalating this problem. And I found someone has post this same problem

Please assist ASAP with this

Microsoft Graph
Microsoft Graph
A Microsoft programmability model that exposes REST APIs and client libraries to access data on Microsoft 365 services.
1,378 questions
Microsoft Graph Files API
Microsoft Graph Files API
A Microsoft API to create an app that connects with files across OneDrive, OneDrive for Business, and SharePoint document libraries.
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Accepted answer
  1. CarlZhao-MSFT 23,686 Reputation points

    Hi @Kanishka Hewapathirana

    I noticed that some members of the community have encountered the same problem recently, and I can also reproduce the problem locally. The Prefer: IdType="ImmutableId request header may no longer be available, I suggest you open a support ticket to confirm with the team. You can raise support ticket from: or

    Hope this helps.

    If the answer is helpful, please click Accept Answer and kindly upvote. If you have any further questions about this answer, please click Comment.

2 additional answers

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  1. Ab-8756 245 Reputation points

    Hello Kanishka Hewapathirana,
    Thank you for your post in this Q&A Forum.

    I have doubled checked with Microsoft resources; I am not seeing any changes done from our end. Here is the Microsoft Graph Changelog article( with the list of changes, addition, Deprecation, Deletion.

    Also the article also mentioned Prefer: IdType="ImmutableId" as an optional feature for Microsoft Graph.
    Could you please try to create a draft message using the Prefer: IdType="ImmutableId" header and then sent the message, once the message is the sent, try to pull up the message with Immutable ID.

    It would be good idea to you create a support ticket with Graph team, if you would like to investigate it further.

    Hope this helps.
    --please don't forget to upvote and Accept as answer if the reply is helpful--

  2. Kanishka Hewapathirana 20 Reputation points

    Hi ,

    Thanks for quick response.

    Here we are already using Prefer: IdType="ImmutableId" concept for email sending and other email based functionalities. They are working fine. As well we have also outlook add-in integrated to outlook email client. On that application , ImmutableId is in use. But this problem is generated when searching email only.

    Please check following details :-


    This is error
    "value": [
                "error": {
                    "code": "ErrorInvalidIdMalformed",
                    "message": "Id is malformed."

    And responses come with 200 status code. That's why it is confused.