The short version
If your team’s emails and meetings appear automatically in Salesforce, there is a connection working in the background. It keeps customer records up to date without someone having to copy everything across.
Microsoft is retiring a technology used by some of those connections: Exchange Web Services, usually shortened to EWS. Salesforce is moving its Microsoft 365 connections to Microsoft Graph.
If your connection still uses EWS, Salesforce advises completing the relevant upgrade before 1 October 2026 to avoid disruption. You may already be on Graph, so the first job is to check.
For a smaller business, the practical questions are straightforward: does anything need changing, who needs to be involved, and how will you know it has worked?
- Microsoft begins disabling Exchange Web Services by default in Exchange Online from 1 October 2026, with permanent shutdown from 1 April 2027.
- If your Salesforce email or calendar sync still connects through EWS, it needs upgrading to Microsoft Graph before that date.
- Einstein Activity Capture, Salesforce Inbox, and Lightning Sync each have their own upgrade route, and the Einstein Activity Capture upgrade cannot be rolled back.
- Check the current connection method in Setup rather than assuming, and confirm the business process still works once the change is made.
What changes on 1 October?
Microsoft begins disabling EWS by default in Exchange Online from 1 October 2026, with permanent shutdown from 1 April 2027.
During that transition, Microsoft provides controls that let administrators temporarily retain EWS access. These require deliberate action by your Microsoft administrator, and they are not an automatic extension for every business.
Plan to have your Salesforce connection checked and any necessary upgrade completed before October. If you cannot meet that date, involve your Microsoft administrator early to assess the temporary options.
This guidance covers Salesforce connections to Microsoft 365 and Exchange Online.
Start by checking what you have
Ask whoever manages Salesforce to identify the tools connecting it to Microsoft 365 and check their current connection method. The relevant settings are here.
| Salesforce tool | Where your administrator should look |
|---|---|
| Einstein Activity Capture | Setup → Einstein Activity Capture → Settings → Summary |
| Salesforce Inbox | Setup → Inbox → Setup Assistant |
| Lightning Sync | Setup → Outlook Integration and Sync → Lightning Sync |
New Microsoft 365 configurations for Einstein Activity Capture and Inbox use Graph from Salesforce’s Spring ’26 release onwards. Older configurations may also have been upgraded already.
Check the current setup rather than relying on when it was installed.
If the relevant connections already use Graph and are working correctly, there is no EWS upgrade left to complete for those connections.
If another supplier provides your Salesforce email or calendar integration, ask them to confirm its status too.
If you use Einstein Activity Capture or Inbox
Salesforce provides a guided upgrade in Setup. A straightforward configuration may be something your existing Salesforce and Microsoft administrators can handle between them.
For Einstein Activity Capture, the process depends on how the connection is managed.
- A connection managed centrally for the organisation. The administrator upgrades the connection, with no action required from individual users.
- Connections authorised by individual users. The administrator starts the upgrade, then each affected user must reconnect their Microsoft account. Until they reconnect, those accounts continue using EWS.
Salesforce provides separate instructions for organisation-level connections and user-level connections.
The EAC upgrade cannot be rolled back to EWS, so confirm the connection type and required Microsoft permissions before starting.
If you also use Inbox, the EAC upgrade can update its authentication at the same time. Check the status of both tools afterwards.
For Inbox on its own, use the upgrade in Inbox’s Setup Assistant. Users must reconnect their Microsoft accounts to complete the transition. Inbox upgrade instructions
If you still use Lightning Sync
Lightning Sync has its own Upgrade to Microsoft Graph option. Your administrators can update the existing connection, and individual users do not need to reconnect.
There is also a longer-term decision to make. Lightning Sync is scheduled to retire in 2027, and Salesforce recommends moving to Einstein Activity Capture. Its current guidance says to upgrade Lightning Sync to Graph before making that migration.
You can therefore deal with the immediate connection change and plan the move to EAC separately. For that later migration, review the contact and calendar behaviour your team relies on, agree the settings you need, and test that the new setup supports them.
Get the right people involved early
You need the person who manages Salesforce and the person who manages Microsoft 365. That might mean two colleagues, an IT provider and a Salesforce partner, or one person wearing several hats.
Before scheduling the upgrade, agree who will approve the Microsoft permissions, who will make the Salesforce change and who will check the result. Having those people available together can prevent a short procedure turning into days of exchanged messages.
Where users need to reconnect, tell them in advance. Explain what the notification will look like, when to act and who to contact if they are unsure. Give them instructions for reconnecting from within Salesforce so they know what to expect.
Check the result before calling it finished
The final step is confirming that the business process still works. Use an affected account to check the functions your team actually uses.
- A new email appears against the expected Salesforce record, where email capture is enabled.
- A new or updated meeting syncs in the direction your configuration allows.
- Contacts sync as expected, if contact sync is enabled.
Allow for your normal sync interval. Where reconnection is required, track who has completed it and follow up with anyone outstanding.
Working email on its own does not prove that the Salesforce connection is working. Include Salesforce in the check, then make sure somebody owns any remaining issues.
A useful moment to check your other connections
While you are reviewing this Salesforce integration, record who owns it and what access it has. Apply the same approach to your other connected systems as you review them.
A simple list of the system, its purpose, its owner and its permissions gives your business a clearer starting point when a supplier changes something or a connection needs attention. It is also a practical foundation for reviewing Salesforce security.
Frequently asked questions
Microsoft begins disabling Exchange Web Services by default in Exchange Online from 1 October 2026, with permanent shutdown from 1 April 2027. Any Salesforce connection that still uses EWS will stop working once EWS is disabled for your tenant. Connections that already use Microsoft Graph are unaffected.
Ask whoever manages Salesforce to check in Setup. For Einstein Activity Capture, go to Setup, then Einstein Activity Capture, then Settings, then Summary. For Salesforce Inbox, go to Setup, then Inbox, then Setup Assistant. For Lightning Sync, go to Setup, then Lightning Sync, then Setup. Each screen shows the current connection method.
It depends on the connection. Einstein Activity Capture handles organisation-level and user-level connections differently, and Salesforce Inbox users must reconnect their Microsoft accounts to complete the transition. Lightning Sync administrators can update the existing connection without individual users reconnecting. Where reconnection is required, tell users in advance what the notification will look like and who to contact.
The Einstein Activity Capture upgrade cannot be rolled back to EWS once it has been made. Confirm the connection type and the Microsoft permissions the upgrade requires before starting, and have your Microsoft administrator available while the change is made.
Sources & further reading
- Exchange Online EWS, Your Time is Almost Up. Microsoft’s retirement timetable, including the 1 October 2026 default disable and the 1 April 2027 permanent shutdown.
- Upgrade Microsoft Office 365 Authentication Method to Microsoft Graph. Salesforce’s overall upgrade guidance for Microsoft 365 connections.
- Einstein Activity Capture: organisation-level upgrade. Steps for org-level connections, and the permissions the upgrade requires.
- Salesforce Inbox: Microsoft Graph migration. The Inbox Setup Assistant route and the user reconnection step.
- Lightning Sync: upgrade to Microsoft Graph. Updating an existing Lightning Sync connection without individual users reconnecting.