A rep creates a meeting on a Salesforce record, sends the invite, and then notices it never appeared on their Outlook calendar. Or the opposite: a customer cancels, the Outlook event disappears, and the Salesforce activity timeline still shows the meeting as happening Thursday. Event sync questions are among the most common Einstein Activity Capture (EAC) support tickets — and most of them trace back to a handful of documented behaviors, not bugs.
The catch is that EAC event sync has rules that surprise people: it matches events by subject and time, it does not backfill existing Salesforce events to Outlook, deletions only propagate when a specific setting is on, and sync conflicts resolve in Outlook's favor. Once you know the rules, the "broken" behavior is usually the designed behavior.
This guide explains how EAC event sync actually works, why meetings created in Salesforce may never reach Outlook, what controls deletion behavior, and how to troubleshoot systematically.
Einstein Activity Capture syncs events between Salesforce and a user's connected Microsoft 365 or Google account based on matching rules, direction settings, and filters your admin controls. Meetings created in Salesforce only sync to Outlook when the user's configuration allows outbound or two-way sync, the user has completed onboarding, and the event is new or updated after connection — there is no initial outbound backfill of pre-existing Salesforce events. Deletions only mirror across systems when the "Remove Deleted Events" setting is enabled.
When Einstein Activity Capture runs event sync, it first tries to match: does an event with the same subject, date, and start and end times exist in both Salesforce and the connected Microsoft or Google calendar? If yes, the two are mapped and begin to sync between the applications. If no match exists, a new event is created on the other side and mapped going forward.
Two scoping rules matter here. First, EAC attempts to match only new Salesforce events (as you create them), existing Salesforce events when you update them, and Microsoft or Google events that fall within the sync filters your admin configured. Second, the sync is intentionally narrow at the start: events on or after the date a user connects their account sync to Salesforce, and admins can adjust the filter window in the configuration's advanced settings.
Sync is asynchronous. Salesforce's own documentation says event sync can take a day or more, and the wait grows when many users start syncing at the same time or large event backlogs are pending. Each user syncs up to 50,000 events; beyond that cap, an additional event only starts syncing when one of the existing 50,000 stops.
This is the scenario behind most tickets. The usual causes, in order of likelihood:
A diagnostic habit that saves time: update one test event in Salesforce (change the description), wait, and see whether the change arrives in Outlook. If the update syncs but older events don't, you're looking at the no-backfill rule, not a broken connection.
Deletion behavior is controlled by an advanced configuration setting called Remove deleted events. When it's enabled, deleting an event on one side deletes the synced counterpart on the other. When it's disabled, deletions don't propagate — which is why one user's calendar shows a cancelled meeting and another's doesn't.
There are two documented wrinkles. If a user deletes a syncing Microsoft event from another user's Microsoft calendar, the Salesforce counterpart is not deleted. And changing an event's owner is deliberately awkward: ownership can't change directly in Exchange or Google, so Salesforce documents a two-step process — the original owner deletes the event in the external calendar and recreates it with the new owner. Whether the original disappears from the first owner's calendar again depends on that Remove deleted events setting.
When sync conflicts occur — the same event edited in both systems before a sync cycle — EAC gives preference to the change made in the external calendar. Mass updates via automation or API calls make conflicts more likely, so teams running calendar automation should expect Outlook-side wins.
| Item | Behavior |
|---|---|
| Custom fields | Don't sync between applications in either direction. |
| Event attachments | Don't sync between Exchange/Google and Salesforce. |
| Formatted description text | Colors and paragraph styles don't sync; with two-way sync, plain text replaces formatting when an event syncs back to the connected account. |
| Bookings with Me events | Outlook Bookings with Me events don't sync between Microsoft and Salesforce. |
| Events with 50+ attendees | EAC syncs up to 50 attendees per event; track larger events (webinars, all-hands) from the external calendar instead. |
| Distribution list members | On inbound sync, individual members of a distribution list aren't synced as attendees. |
| All-day events | Sync from Microsoft to Salesforce as 24-hour events. |
Organizer rules also surprise people: an organizer who creates an event in Salesforce can only invite attendees who are Salesforce users, contacts, or leads. External guests must be invited from the external calendar. And events that can't be related to a lead or contact land in the user's Unresolved Items list unless the configuration's "Relate Synced Events to Salesforce Records" setting is on.
When a user reports missing or zombie meetings, work this order before opening a Salesforce case:
Document your event-sync policy the way you document email handling: which direction syncs, which date filters apply, whether deletions propagate, and who owns changes. Most EAC frustration comes from users discovering the defaults by accident. A one-page internal guide — "create customer meetings here, cancel them here, expect changes within a day" — eliminates most tickets.
If you're migrating from Salesforce for Outlook or Lightning Sync, treat event sync as a design decision, not a checkbox. The retired tools behaved differently, and users' muscle memory will be wrong until you retrain it.
Vantage Point's Salesforce consultants configure Einstein Activity Capture as part of a broader productivity design — sync direction, filters, deletion behavior, and the activity-timeline settings that decide what shows up on account and contact records. Our Salesforce implementation and advisory team handles the initial design, and our managed services team owns the ongoing "why didn't this sync" questions so your admin doesn't have to.
Vantage Point has untangled Salesforce–Outlook sync for teams across more than 400 engagements. Talk to us about your activity capture setup — most sync mysteries resolve to a settings conversation, not a rebuild.
It can, but only when the admin's EAC configuration enables outbound or two-way event sync. Many orgs run inbound-only (Microsoft 365 to Salesforce), in which case events created in Salesforce intentionally never appear in Outlook.
There is no initial outbound sync from Salesforce to Exchange or Google during onboarding. Existing Salesforce events only begin syncing after you update them, and only new events sync as you create them.
Deletions only propagate when the configuration's "Remove deleted events" advanced setting is enabled. Without it, deleting an event on one side leaves the counterpart on the other. There are also documented exceptions, such as deleting a syncing event from another user's Microsoft calendar.
Event sync can take a day or more, per Salesforce's documentation. Wait times grow when many users onboard simultaneously or large backlogs are pending. EAC syncs up to 50,000 events per user.
The external calendar wins. When the same event changes in both systems before a sync cycle, Einstein Activity Capture gives preference to the Microsoft or Google change.
No. Custom fields don't sync in either direction, event attachments don't sync, and formatted description text is replaced by plain text when an event syncs back to the connected account. Outlook Bookings with Me events don't sync at all.