GraphAPI GCC High - Differences in uploadsession VS Public?

Austin Clarke 1 Reputation point

Our team is attempting to send emails with attachments greater than 3MB via the GraphAPI. From my understanding, this requires implementation of uploadsession. When testing the code with public endpoints or GCC endpoints, it works without error. When testing the code in our GCC High environment, we hit the following errors:
Message: The OData request is not supported.
HTTP/1.1 405 Method Not Allowed

So my question is: Are there any special considerations when implementing uploadsession in the GCC High environment beside the endpoints (*.us)? I should note that we authenticate successfully and can send and retrieve mail items including retrieving mail items with attachments greater than 3MB. It is only when attempting to attach and send an email with a >3MB attachment (implementing uploadsession) that we run into this issue.

Any help would be greatly appreciated!

Microsoft Graph
Microsoft Graph
A Microsoft programmability model that exposes REST APIs and client libraries to access data on Microsoft 365 services.
10,874 questions
0 comments No comments
{count} votes