Update 3/27/2025: We updated the "Access to public folders" section below.
This post is a part of our EWS (Exchange Web Services) to Microsoft Graph Migration Guide Series.
In 2018, we announced ...
Updated Mar 27, 2025
Version 5.0
Blog Post
Few years ago, when we investigated replacing our EWS solution with Graph API, I became aware of the following issues. Some are based on our own research, some are from other comments, so take the list with a grain of salt.
- Graph API is not supported by on-premise Exchange Servers.
- Graph API does not make it possible to access distribution lists.
- Graph API does not appear to make it possible to upload MIME messages longer than 3 MB to mailbox.
- Graph API does not appear to make it possible to send MIME messages longer than 3 MB.
- Graph API cannot send encrypted or signed e-mails if larger than 3 MB (due to the limitations above).
- Graph API does not provide any way to get full-fidelity (preserving all properties) email information into and out of Office 365 (see MS-OXWSBTRF).
- Graph API doesn't provide a method to copy/move content from one mailbox to a different mailbox.
- Graph API is unable to access public folders.
- Graph API does not support contact lists.
- Graph API does not appear to support streaming notifications. Web hooks are impractical due to the need of maintaining server-side application.
- Graph API has no roadmap to gain feature parity with EWS.
Has any of these been resolved in the meantime?
Particularly the strange approach to MIME and S/MIME was a showstopper for us back then.