If your EWS applications stopped working and you are looking for a quick relief, please see Exchange Online EWS application stopped working? Do this. | Microsoft Community Hub. Re-enabling EWS is pos...
Updated Oct 27, 2026
Version 21.0
Blog Post
Dear Microsoft team, we are building multiple end-user facing email apps, including Thunderbird Owl, ExQuilla, Parula and Mustang. We have tens of thousands of users on Owl alone, and good part of them use EWS protocol on Office 365. We have implemented Graph in most of our products, but after having finished development, we find that we cannot actually deploy it, because Microsoft blocks access to Graph email for all applications by default . This was a change that happened in October 2025 (less than 1 year ago), and we were not aware of that.
So, now we have an existing userbase that we're forced to migrate to a new protocol, we have invested into implementing it, we implemented a smooth migration path for end users, are about to deploy it, and find that it's categorically impossible for users to log in, because you're blocking it.
Only a very short list of very popular email applications, including Apple Mail and Thunderbird are on that list. We are actually co-authors of Thunderbird, but as Open-Source, so not the same organization. Note that any solution that requires explicit admin approval will not work in practice for a public client with many users as ours.
How can we get on that list of approved email clients allowed by default? This is URGENT, we were about to deploy and found out only in our QA phase that login is now blocked. Please help us TODAY at parula (dot) support (at) beonex.com . Thank you.