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Summary: This article addresses common Outlook issues on MacOS, including crashes, search failures, flickering screens, error codes, email problems, and account openings. It emphasizes the use of a professional OLM repair tool for file corruption. Solutions are provided for each problem, and the importance of using a specialized tool like Kernel OLM to PST Converter for OLM file corruption is highlighted.

Outlook for Mac was first launched by Microsoft in 2011. Since then, it has undergone several updates across different versions. The user interface of Outlook is tailored to match the macOS environment, and it boasts distinct features compared to its Windows counterpart.

Typically, Outlook for Mac operates seamlessly without encountering any errors or issues that might hinder the mailbox’s accessibility or the sending/receiving of emails. However, if you do encounter difficulties such as Outlook failing to open or encountering other errors, it is advisable to peruse the entire article and apply the relevant methods tailored to your specific issue.

Issue-1. Outlook is crashing unexpectedly on startup

If a user adds a new account and synchronization is interrupted by an application crash, Outlook will display the following screen:
added a new account and synchronization

Cause – Outlook crashes during the account synchronization when the calendar event has a ‘NULL OriginalStart’ property.

Solution – Before linking it to Outlook for Mac, you have the option to delete the calendar event from your account. If you’ve already integrated the account, ensure that you’ve updated the application to at least version 16.47.

Navigate to the toolbar and select the ‘Help’ option, then click on ‘Check for Updates.’

click Check for Updates

An update for Outlook is pending; click it to update.
click it to update

Issue-2. Searches in Outlook are not recovering results

At times, individuals utilizing the earlier iteration of Outlook for Mac on macOS Big Sur encounter an issue where search outcomes either yield no results or display restricted information.

Solution – To resolve the search results issue, follow these steps: Modify the file association and reindex Spotlight to align with the updated version of Outlook for Mac.

  1. In the Apple Menu, go to System Preferences and choose Spotlight.
  2. In the Privacy tab, go to Finder.
  3. On the Go menu, select go to Folder.
  4. Choose the following location and paste its complete path in the ‘Go to the folder’ dialog box,
    ~/Library/Group Containers/UBF8T346G9.Office/Outlook/Outlook 15 Profiles/
  5. Now, drag the mail folder to the Privacy tab. After adding it, remove the folder, and Spotlight will re-index with the new folder.
Issue-3. Outlook screen is flickering in iMac computers

When the user is running macOS Mojave on iMac computers, some users may face a challenge that Outlook starts to flicker.
Solution – The issue arises when you have a 27-inch Retina iMac. If you intend to utilize Outlook for Mac, you’ll need to either reinstall the application or reboot the machine.

Issue-4. Error-17099 and Error-3253 while sending an email with an attachment

If you encounter errors like 17099 and 3253 while attempting to attach a file or zipped file in Outlook for Mac, consider sending it through alternative methods individually.
Solution – The issue arises with Norton Security for Mac version 8.6.3 or newer. Norton has recently released a hotfix to address this problem.

Issue-5. The user cannot send or receive emails in Outlook for Mac

The most significant problem a user encounters when email communication halts entirely is the cessation of incoming and outgoing messages in their mailbox.
Cause- There can be multiple causes behind the problem-

  • The computer does not have an Internet connection.
  • IMAP/POP accounts require authentication.
  • ISP or network firewall has stopped emails by blocking them.
  • The email server is unavailable.
  • Account credentials are saved incorrectly.

Solution – For each cause, you should use an appropriate solution.
Check Internet connection.

  1. Verify the status of the Internet cable, Wi-Fi router, and any other potential connection issues.
  2. In the Outlook menu, make sure that the ‘Work Offline’ option is unchecked.

Authenticate your account.

  1. Follow Tools>>accounts.
  2. In the Account box, choose the account.
  3. In the Outgoing server, choose More options.
  4. Choose your authentication type and input the correct credentials.

Input email server address.

  1. In the Tools menu, choose Accounts. Then, choose the account.
  2. In the outgoing server box, input the current email server address for IMAP/POP/SMTP accounts.
Issue-6. An account is not opening in Outlook for Mac

If the account isn’t opening fully, it may be because the OLM file associated with the account is corrupted.
Solution – If you know about OLM file location in MAC Outlook, To regain access to your account content and reattach it to Outlook, it is imperative to mend the corrupted OLM file. While there are free methods available for converting OLM to PST, they tend to be quite time-intensive. The Kernel OLM to PST Converter, however, provides an efficient solution, allowing you to retrieve data from damaged OLM files and seamlessly export them into PST format.


If Outlook encounters issues on a Mac, you may try troubleshooting for internet or server-related problems manually. However, when faced with a corrupt OLM file, rectifying the corruption isn’t straightforward. In such cases, employing a specialized OLM repair tool like Kernel OLM to PST Converter is recommended. This software enables you to recover the entire mailbox and store it in PST format efficiently.

Kernel for OLM to PST