We develop an Outlook Office addin that calls addFileAttachmentAsync(url, filename).
The attachment download url points at our webapp with url like: https://serverhost/api/v1/contentlib/getResource?authToken=xxxxx&&resourceAbsUrl=yyyy&key3=val3
- This works as expected in Outlook 2016 desktop and Chrome browser (OWA). Attachment is downloaded from the server and added to email.
- Doesn't work in Outlook 2016 insider version 16.0.8201.2025
Error msg: Download failed (under the attachment).
When used fiddler (can also 'Open File Location' from the failed attachment dropdown menu) --> it seems Outlook requests the url without the query string. e.g https://serverhost/api/v1/contentlib/getResource
The length of the url is below 2048 - the documented max.