What you’re seeing
- A CRM, archiving tool, scanner or calendar-sync service that worked for years now logs authentication or 'access denied' errors when reaching Microsoft 365 mailboxes.
- Email that used to be filed into the CRM automatically stops appearing, without any visible error in Outlook.
- Room booking displays, Mac mail apps or older Outlook-for-Mac versions stop loading mailbox data.
- Vendor support says the product needs an upgrade or a newer connector to keep working.
Common causes
Every environment is different, but these are the causes our engineers find most often:
- Microsoft is retiring Exchange Web Services in Exchange Online, disabling it by default starting in October 2026 ahead of a full shutdown.
- The application was built on EWS and the vendor has not yet moved it to Microsoft Graph, or the business is on an old version that never will be.
- An organization-level EWS setting or app allow list now blocks applications that are not explicitly permitted.
- Legacy basic authentication, which many EWS-based tools also relied on, was already switched off and the app never moved to modern auth.
Why it matters
EWS dependencies are often hidden: the CRM that logs emails, the backup tool for mailboxes, the conference-room panels or a document management system. When they fail, data silently stops flowing, and nobody notices until a backup is needed or a client record is missing weeks of correspondence. Replacing or upgrading these tools on a deadline is far more expensive than planning it. Knowing which systems depend on EWS lets the business budget and schedule the change instead of reacting to outages.
How AskTechGurus fixes it
Skip the trial and error. A certified engineer works on your actual system, finds the root cause, and fixes it properly.
Tell us what’s happening
Submit a ticket in about two minutes. Paste the error, describe what changed, and pick your tier. No charge to submit.
A certified engineer diagnoses it
A vetted, US-based systems engineer claims your ticket, usually within minutes during business hours, and investigates over a secure remote session you can watch and end at any time.
Fixed and verified with you
The engineer resolves the root cause and confirms with you that it’s working. You don’t just get a workaround, and you get a plain-English summary of what was wrong.
Pay only when it’s resolved
Fixed price from $99, invoiced only after you approve the fix. If it isn’t resolved, you don’t pay.
Frequently asked questions
Can we keep using our old app?
Only for a limited time, and only if Microsoft's temporary allowances still apply to your tenant. Long term, the app needs a version that uses Microsoft Graph or a replacement product.
How do we find out which tools use EWS?
Microsoft 365 records EWS usage, and an engineer can match those entries to the products you run. Vendors can usually confirm their roadmap once you know which version you have.
Can AskTechGurus help us plan this?
Yes. A certified US engineer reviews your EWS usage and connected apps in a remote secure session, from $99, and you pay only when it's resolved.