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
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I guess some of that list was created over 3 years ago? 😉
Yes, that's about right! 🙂
But some are newer. Last time we checked, in June 2022, maximum outgoing MIME message size was limited to only 3 MB. Will try again soon and report back.
luberth
As I wrote above, the issue was not lack of MIME support, but rather the limitation to 3MB message size (which seemed undocumented). This is the approach we ended up with last year when we last investigated Graph API as a replacement for our EWS client:
1. If the message is shorted than 3MB, send it using the sendMail API method that does accept MIME (unless larger than 3MB).
2. If the message is longer than 3MB, create a draft message based on the MIME message content, upload attachments individually, and send the message.
Of course, the second approach was imperfect because instead of sending the actual MIME message, a new one was constructed from scratch based on the original's content. At that point, it seemed more reasonable to keep using EWS or switch to good old SMTP.
Is there any page where I can track MS Graph API updates, particularly those related to e-mail APIs?