Outlook for Mac: Known Bugs and Proven Fixes
Outlook for Mac users often encounter a range of common issues that can disrupt their workflow. Fortunately, many of these problems can be resolved by installing the latest updates or performing some basic troubleshooting steps. In this guide, we’ve identified the most frequently reported issues and provided simple, effective solutions to help you resolve them quickly and get Outlook running smoothly again.
Microsoft Outlook is one of the most widely used email clients, known for its ability to manage emails from various accounts within a single interface. Its powerful features and user-friendly design make it a preferred choice for many Mac users as their default email application.
That said, Outlook for Mac isn’t without its challenges. Users often report issues such as trouble signing in, calendar syncing problems, and other technical glitches. If you’ve been experiencing similar problems, don’t worry most of them can be resolved with simple fixes.
In this article, we’ll cover some of the most common Outlook for Mac issues and provide clear, step-by-step solutions to help you troubleshoot and resolve them efficiently.
Troubleshooting Table: Outlook for Mac Common Problems & Solutions
| Issue | Cause | Solution |
| Sign-in error | Wrong credentials, outdated app | Update Outlook, check login details |
| Calendar not syncing | Sync settings, server issue | Refresh, re-add account |
| App crashing | Corrupt profile, old version | Update app, clear cache |
| Search not working | Indexing issue | Rebuild Spotlight/Outlook index |
| Email not sending/receiving | Server or network issue | Check settings, restart Outlook |
| Repeated password prompts | Keychain or expired login | Reset credentials, update Keychain |
| Slow performance | Large mailbox, add-ins | Archive mail, disable add-ins |
| Attachment issues | Security or sync problem | Check settings, use webmail |
| Office 365 sync error | Connection/auth problem | Reauthenticate, check Office status |
| App won’t open | Corrupt install/macOS issue | Reinstall app, update macOS |
How to Fix Common Issues in Outlook for Mac: Step-by-Step Solutions
Issue 1: “Reply,” “Reply All,” and “Forward” Buttons Not Responding
Sometimes, the Reply, Reply All, and Forward buttons in Outlook for Mac may stop functioning properly. This issue is often caused by using an outdated version of Microsoft Office. Fortunately, updating to the latest version usually fixes the problem.
Here’s how to check for and install Office updates:
- Open any Microsoft Office application, such as Word. From the top menu bar, click Help and select Check for Updates.
Note: If you don’t see the Check for Updates option, you might need to download or update the Microsoft AutoUpdate tool first. After updating it, try this step again.
- In the Microsoft AutoUpdate window, make sure to select Automatically keep Microsoft Apps up to date. This will help your apps stay current with the latest security patches and feature enhancements.
- Click Update to download and install any available updates.
Issue 2: Attachments and Inline Images Not Sending in Signed or Encrypted Emails
Some users of the new Outlook for Mac have reported problems when sending signed or encrypted emails specifically, attachments and inline images sometimes fail to send correctly. This issue has been identified in certain versions of the new Outlook experience.
Solution: This problem was resolved starting with Outlook for Mac version 16.66. To fix this error, make sure your Outlook is updated to version 16.66 or newer. You can follow the update steps described in Issue 1 to check for and install the latest version.
Issue 3: New Outlook for Mac Freezes When Using Search
A number of users have reported that the new Outlook for Mac crashes or becomes unresponsive when they use the search function. The issue occurs specifically when the search suggestions dropdown is triggered.
Solution: This behavior is caused by a recent service update designed to enhance search performance. However, this update inadvertently causes the app to crash for certain search queries. Reverting this update will resolve the problem, allowing Outlook for Mac to operate without freezing.
Issue 4: Outlook for Mac Crashes During Email Sync and Startup
Users may experience Outlook for Mac crashing when synchronizing emails or during the application’s startup. This issue can also occur after adding a new account. The crash happens regardless of whether a calendar event has a NULL OriginalStart property. Additionally, a Microsoft Error Report may appear, suggesting that you update your Outlook client.
Solution: Microsoft has addressed this problem in the latest update. Installing Office updates version 16.47 or newer will resolve the crashing issues. Make sure to update your Outlook to the latest version to fix this problem.
Issue 5: “Account Already Exists” When Adding a Mailbox in Outlook for Mac
You might encounter the “Account already exists” error while trying to add a mailbox in Outlook for Mac, particularly when adding a shared mailbox through the main “Add email account” window.
How to Fix It: Close the error pop-up and go back to the main Accounts screen. Check if your primary email account is already added. If it’s not, you must add your main account first before you can add any shared mailboxes.
After adding your primary account, follow these steps:
- Navigate to Delegation and Sharing.
- Select Shared with me.
- Click the plus (+) icon located at the bottom-left corner.
- Add the shared mailbox from there.
Issue 6: Outlook Attachment Sending Errors: Fixing -17099 and -3253
If you encounter Outlook errors 3253 or -17099 when trying to send an email that includes an attachment, the problem is often linked to the Vulnerability Protection module in Norton Security for Mac version 8.6.3 or later. Fortunately, Norton has released a hotfix that addresses this conflict and resolves the sending error.
Issue 7: Outlook for Mac Attachment Access Denied Because of Helper Application
Some Outlook for Mac users see the error message: “The file ‘filename.ext’ could not open because you don’t have permission to view it.” This usually happens when a helper application is running on macOS version 11.6.6.
Solution: Installing the macOS update 11.6.7 fixes this issue. If you haven’t updated yet, you can work around the problem by closing the relevant helper app. For example, if you’re trying to open a PDF file that uses Preview as the default viewer, simply quit Preview before reopening the attachment.
You may also like – How to Save OLM File as PDF
Issue 8: Unable to Create New Signatures and Missing Existing Ones in New Outlook for Mac
After installing the Office for Mac update version 16.63, users are unable to create new email signatures using the plus (+) button, and their existing signatures may disappear.
Solution: This problem is fixed in the newer Outlook for Mac update, version 16.64. Updating to this version will restore signature functionality.
Issue 9: “To,” “CC,” and “BCC” Fields Shortened After Outlook for Mac Update
Following the installation of update 16.57 for the Legacy Outlook for Mac, some users notice that the “To,” “CC,” and “BCC” fields appear shortened when composing emails.
Solution: This issue has been resolved in the Mac Beta Channel version 16.58 (Build 220106). Updating your Legacy Outlook for Mac to this version will correct the email field display.
The Concluding Words!
In the article above, we’ve highlighted some of the most common problems that Outlook for Mac users often face. These issues are typically straightforward to resolve by updating to the latest version of Outlook for Mac or, in some cases, by upgrading to the newest macOS version. However, if the solutions provided here don’t fix your Outlook for Mac problems, you might want to try MacArmy OLM Converter for Mac. This software uses advanced technology to smoothly convert OLM files into various formats like PST, PDF, MBOX, EML, MSG, DOC, HTML, CSV, Office 365, Gmail, Thunderbird, Outlook.com, Yahoo Mail, IMAP, and so on. MacArmy’s OLM to PST Converter is a powerful tool designed to meet the needs of both technical experts and professional Outlook for Mac users.
Moreover, the user-friendly interface makes it easy for even non-technical users to operate the converter without any hassle. It supports batch conversion, which saves time by processing multiple OLM files simultaneously. This makes MacArmy OLM File Conversion an ideal choice for both individual users and organizations looking to manage their Outlook data effectively.
Important Tips – Try the Demo Version of MacArmy Outlook for Mac Migration Tool
Before purchasing the full version, you can try the demo version of MacArmy OLM Export for Mac to evaluate its features and functionality. The demo allows you to scan and preview all your Outlook for Mac OLM files, including emails, attachments, contacts, and calendars. This way, you can verify the tool’s effectiveness and ensure it meets your needs. However, please note that the demo version has limited functionality and does not support saving or exporting the converted files. To unlock full capabilities, upgrading to the licensed version is necessary.
