The internet message header name 'List-Unsubscribe' should start with 'x-' or 'X-'.

[tang2087]

Describe the bug
When sending email message using Graph API, an ODataError exception will throw out if List-Unsubscribe header is added:
"The internet message header name 'List-Unsubscribe' should start with 'x-' or 'X-'."

To Reproduce
Steps to reproduce the behavior:

1. Create a message with internet message header:

var emailMessage = new Message
{
    Subject = subject,
    Body = new ItemBody
    {
        ContentType = BodyType.Html,
        Content = body
    },
    InternetMessageHeaders = new List<InternetMessageHeader>
    {
        new InternetMessageHeader { Name = "List-Unsubscribe", Value = listUnsubscribe }
    }
};

2. Send the email using Graph API and the exception will show up.

Expected behavior
Email sent successfully without exception.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
Add any other context about the problem here.

[andrueastman]

Thanks for raising this @FahaoTang,

As this seems to be an API side related issue and this repo is mainly intended for SDK related issues, any chance you can post the query at the link below to get feedback from the API owners? It would be great if you could post back the link to the created question so that anyone who comes across this may find it helpful as well.

https://learn.microsoft.com/en-us/answers/tags/161/ms-graph

[microsoft-github-policy-service]

This issue has been automatically marked as stale because it has been marked as requiring author feedback but has not had any activity for 4 days. It will be closed if no further activity occurs within 3 days of this comment.