v1
latestOpenAPI 3.0.42026-07-174835104.5 KBusers.message
Create large file attachment upload session from user
Create an upload session that allows an app to iteratively upload ranges of a file to attach to a message in a specific user's mailbox.
post/users/{userIdentifier}/messages/{messageId}/attachments/createUploadSession
Request body
Response
Success - returns an upload session