Mac outlook desktop showing dfferent contacts to office 365 online

Julian Scott 0 Reputation points
2026-10-10T13:49:20.14+00:00

I have over 4,000 contacts when I log in online, but I deleted all your contacts from my Mac Outlook account. I can sync between BusyContacts and Outlook on my MacBook, but these changes aren't reflected online or on my iPhone. One other thing - my OneDrive and Office 265 account show my email address then :1

Any thoughts would be greatly appreciated.

Outlook | MacOS | New Outlook for Mac | For business
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  1. Roebe Ta 1,550 Reputation points Independent Advisor
    2026-10-10T14:30:33.17+00:00

    Hello @Julian Scott,

    Good day! I hope you are doing well.

    Thank you for reaching out. To help us provide the most accurate and effective solution, could you please share a bit more information about your setup and the issue you're experiencing?

    • As this thread is categorized under New Outlook for Mac, can you confirm if it is your Outlook version or you use Legacy Outlook for Mac or both?
    • Is your account configured as a Microsoft 365/Exchange account or another type of account (such as IMAP)?
    • Have you made any recent changes to your Outlook profile, account configuration, or contact synchronization settings?
    • Have you already tried removing and re-adding the account in Outlook for Mac? If so, what was the result?
    • You mentioned that you can sync between BusyContacts and Outlook on your Mac. Could you confirm whether BusyContacts is connected to your Microsoft 365 account using Microsoft Graph?
    • If possible, could you provide screenshots (with your personal information removed) showing:
      • The contacts visible in Outlook on the web
      • The contacts visible in Outlook for Mac
      • The account showing with the ":1" suffix

    This additional context will help better understand your environment and any troubleshooting steps already taken, allowing us to tailor our recommendations more effectively.

    In the meantime, as an initial check, please verify whether the contacts displayed in Outlook for Mac are associated with the same Microsoft 365 account that contains the 4,000+ contacts visible in Outlook on the web. The account name displaying with a ":1" suffix may indicate that a duplicate account or profile has been configured, which could potentially contribute to synchronization inconsistencies.

    If some contacts are not appearing across Outlook on the web, Outlook for Mac, BusyContacts, or your iPhone, please try the following:

    • Ensure you're signed in with the correct Microsoft 365 account.
    • Verify that contact synchronization is enabled for the account.
    • Refresh the contacts list in BusyContacts by selecting View > Refresh or pressing ⌘R.

    After performing these steps, please test by creating a new contact and checking whether it appears across all devices and applications. This will help determine where the synchronization is breaking down.

    You may find this article helpful: Using BusyContacts with Office 365 (Microsoft Graph) | BusyCal & BusyContacts

    (Note: This link is shared by community members for your convenience. It points to a third-party site that is not managed or verified by Microsoft. We can’t guarantee the quality, safety, or suitability of any content or software found there. Please review carefully and make sure you understand any potential risks before using it.)

    I look forward to your response and will be happy to continue working with you to get this issue resolved. Kind Regards.

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