Hello Stack Overflow community,

I am working on a Java project using Microsoft Graph SDK and I am encountering an issue while trying to retrieve the content of an attachment of type message/rfc822. I am able to get other attachments (like FileAttachment) without any issues, but I am struggling to load the content of ItemAttachment.

Here is a snippet of my code:

AttachmentCollectionPage attachments = graphClient.users(request.getUser())
                .messages(request.getId())
                .attachments()
                .buildRequest()
                .get();

for (Attachment attachment : attachments.getCurrentPage()) {
    if (attachment instanceof FileAttachment) {
        FileAttachment fileAttachment = (FileAttachment) attachment;
        byte[] contentBytes = fileAttachment.contentBytes;
        // Handle file content
    } else if (attachment instanceof ItemAttachment) {
        ItemAttachment itemAttachment = (ItemAttachment) attachment;
        // Handle item attachment
        // The item field is always null
    }
}

The ItemAttachment has the following properties:

item = null
contentType = "message/rfc822"
id = "some-id"

I have already looked at this post How to retrieve contents of an itemAttachment via the Microsoft Graph API, but I still don’t understand how to achieve this using the SDK.

After further research, I found that to retrieve the content of an ItemAttachment, I need to append /$value to the URI.

However, I am not sure how to implement this using Microsoft Graph SDK for Java. I have not tried using customRequest because I am looking for a cleaner solution within the SDK itself.

Is there a more straightforward way to retrieve the content of an ItemAttachment using Microsoft Graph SDK for Java? Any help or guidance would be greatly appreciated.

Thank you!