How to recover data missing from Outlook for Mac desktop version

Question

How to recover data missing from Outlook for Mac desktop version

RITA MUJRAL 0

I left work on Friday and everything was working fine in my microsoft outlook for mac desktop product. Today I logged in and all of my calendars were missing from the new version. All it said was, Add Calendar.

I then went back to the legacy version where the calendars showed all my backed up olm files as well as calendars BUT about 3 months of recent data was missing.

I did many steps of troubleshooting:

created a new data profile

tried to import two different OLM files, neither worked in legacy to show past 3 months of data

un-installed outlook app and re-installed

un-installed againa and then re-installed a month old version of outlook for mac

I tried to import two old OLM files to the newly downloaded version and both times nothing changed. This is extremely frustrating as I dont remember any of my mtgs this week and old data has disappeared which was invaluable. Pls help...

RITA MUJRAL 0 Reputation points

2026-07-20T21:58:11.6266667+00:00

Thank you for the info, let me provide a bit more info. I am the IT Admin. I am using Imap and the OLM file was from Friday. I am the only person who is using this Outlook for Mac desktop version. There is no one to contact for help. Please let me know if any updates were done that would wipe out the last 3 months in legacy Mac. These same calendars aren't showing up in the new version now. It was working fine for a few weeks since I made the switch. One more thing, when I search my calendar, I find events from last week but they aren't showing up when I look at my calendar.

1 answer

Your answer

RITA MUJRAL 0 Reputation points

2026-07-20T21:58:11.6266667+00:00

Thank you for the info, let me provide a bit more info. I am the IT Admin. I am using Imap and the OLM file was from Friday. I am the only person who is using this Outlook for Mac desktop version. There is no one to contact for help. Please let me know if any updates were done that would wipe out the last 3 months in legacy Mac. These same calendars aren't showing up in the new version now. It was working fine for a few weeks since I made the switch. One more thing, when I search my calendar, I find events from last week but they aren't showing up when I look at my calendar.

Answer 1

Kai-L 18,725 Microsoft External Staff Moderator

Dear RITA,

Good day, and thank you for the detailed description of your issue.

I'm truly sorry to hear about the situation, you have already spent considerable time troubleshooting, and losing visibility of three months of calendar appointments is understandably alarming, particularly when you need this week's meeting schedule immediately. As a forum moderator, I am not able to access your mailbox or investigate the missing calendar items from my side. My role here is limited to providing general guidance and pointing you toward the right recovery path. Based on your description and my research:

OLM files are point-in-time archives, not continuously updated backups. If your OLM files were created more than three months ago, they will not contain the recent appointments, so importing them will not bring back the missing three months.
Creating a new Outlook profile does not repair or merge the old profile. It gives Outlook a completely separate data environment, so your recent local calendar data may still be present in the previous profile.

The good news is that if the calendar items were ever synced to your Exchange Online mailbox, they are almost certainly still recoverable on the server side, which is where the real recovery should happen.

If this is a work mailbox, I would recommend reaching out to your IT administrator. Ask them to check the following in your Exchange Online mailbox:

Deleted Items folder and the Recover Deleted Items option (also known as the Recoverable Items folder).
Any active retention policies or preservation holds on the mailbox.
Calendar diagnostic logs for the affected time period.
Audit information around any recent deletions or account changes.
Whether the calendar items still exist in Exchange Online but are not syncing to the Mac client.
Whether the affected calendar was shared, delegated, or stored in another mailbox you have access to.

If you don't know who your IT administrator is, please refer to this article: How do I find my Microsoft 365 admin? - Microsoft Support

As a last resort, the Global Admin in your organization can open a service request with Microsoft Support on your behalf. A technical support engineer can review the mailbox recovery options, verify whether the calendar items are still present in Exchange Online, and coordinate any additional recovery steps that go beyond the standard user tools. If needed, they can also escalate the case to a specialized team for deeper analysis. For detailed instructions on how to get support, please refer to Get support - Microsoft 365 admin.

While the recovery is being investigated, you can check whether your calendar items are still visible in Outlook on the web by signing in at outlook.cloud.microsoft with the same work account. If the items appear there, this confirms they are still on the server, and the issue is only with the Outlook for Mac client sync, not actual data loss. That would also give you immediate visibility to this week's meetings while the recovery work happens.

I truly hope you get this resolved swiftly. Please know that even though I cannot directly intervene, pointing you toward the correct, specialized support is genuinely the most effective help I can offer from my position. Thank you for your patience and understanding. Please let me know if you need anything else. Wishing you all the best.

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RITA MUJRAL 0 Reputation points

2026-07-21T12:26:53.6966667+00:00

Thank you for the info, let me provide a bit more info. I am the IT Admin. I am using Imap and the OLM file was from Friday. I am the only person who is using this Outlook for Mac desktop version. There is no one to contact for help. Please let me know if any updates were done that would wipe out the last 3 months in legacy Mac. These same calendars aren't showing up in the new version now. It was working fine for a few weeks since I made the switch. One more thing, when I search my calendar, I find events from last week but they aren't showing up when I look at my calendar.
Kai-L 18,725 Reputation points Microsoft External Staff Moderator

2026-07-21T21:09:28.4133333+00:00
Dear RITA,

My apologies for the delayed response, and thank you for the additional details, this significantly changes the picture and helps clarify what is likely happening. The key detail is that you are using IMAP to connect Outlook for Mac to your mailbox. This is important because IMAP does not support calendar or contact synchronization, it is a mail-only protocol. Calendar data in an IMAP-configured account is stored locally in Outlook's data file on your Mac, not on the server.

This means:

Your calendar data lives only in the local Outlook profile, not in the cloud or on the mail server.

If the local data becomes corrupted, incomplete, or is affected by a profile / OLM issue, the data is at risk because there is no server-side copy to sync back down.

The fact that search finds events from last week but they do not display in the calendar view strongly suggests the events still exist in the local data file, but the calendar view is not rendering them correctly. This is more likely a calendar view / cache issue than actual data loss.

Given the complexity and the risk to your local data, I would highly recommend opening a service request with Microsoft Support so a technical engineer can investigate this properly on your Mac. For step-by-step instructions on how to open a support ticket, please refer to my previous reply.

Once you have the support ticket ID, please feel free to share it with me here through a private message, and I will do my best to keep you updated as the case progresses. You can open private messages at your post:

In the meantime, please try the following safe checks while the support case is being opened:

In the Outlook for Mac calendar view, check that no filters are accidentally applied (e.g., viewing only "Today", "Work Week", or a specific category). Try switching to Month view and navigating back to check the missing months.

In the left navigation pane, make sure the correct calendar is checked (highlighted). If you have multiple calendars, the missing events may be assigned to a different calendar that is currently toggled off in the display.

Since the data is likely still intact but simply not displaying, importing another OLM file at this stage could complicate the situation. Please hold off on any further imports until the view issue is resolved.

Longer-term recommendation

Since IMAP does not sync calendars or contacts, you are essentially operating without a server-side backup for those items. To protect against future data loss, I would strongly recommend considering one of the following:

Switch the account to Exchange if your mailbox is on Exchange Online or another Exchange server. This gives you full server-side sync of calendars and contacts, so any local issue never affects the actual data.

Regularly export calendar data to OLM as a manual backup routine.

Consider migrating to a Microsoft 365 mailbox if you are not already on one. Microsoft 365 uses Exchange by default and provides the full server-side sync you are currently missing with IMAP.

I hope this information is helpful. Please let me know if you need anything else.
Kai-L 18,725 Reputation points Microsoft External Staff Moderator

2026-07-27T20:40:50.84+00:00

Dear RITA,

It has been a while and I am writing to see how things are going with this issue. If there’s anything else I can assist you with or if you need further clarification, please don’t hesitate to let me know, I’m here to help. Looking forward to hearing from you. Wishing you a great day ahead!
RITA MUJRAL 0 Reputation points

2026-07-27T20:53:41.2866667+00:00

It was a lot of trial and error. It looks like a few of my olm files were corrupt. That is the conclusion we came to. Something happened where everything on my calendar disappeared last Monday. Now I have been able to recover everything prior to June 12th from an older olm file. Still I feel Microsoft did something upgrade or something that caused this. Not sure. I just have to deal with the loss of the data at this point.
Kai-L 18,725 Reputation points Microsoft External Staff Moderator

2026-07-27T21:19:42.6533333+00:00

Dear RITA,

Thank you for coming back to share the outcome, and I'm genuinely sorry it came to this. I'm glad you were at least able to recover everything prior to June 12th from an older OLM file. That is a meaningful recovery given the circumstances, and it is a credit to your persistence that you got that far. Going forward, given that IMAP does not sync calendars or contacts to the server, I would gently suggest putting a simple backup routine in place so you are never in this position again. A monthly OLM export, or better yet, switching the account to Exchange or Microsoft 365 (which keeps everything server-side and recoverable), would give you a proper safety net. Thank you again for updating the thread. I truly wish the outcome had been better, and I am sorry you lost that data. If anything else comes up, or if you decide to look at moving to a server-synced setup, please feel free to reach out anytime.

Wishing you all the best.