How to Fix Microsoft Outlook 2011 for Mac Error Code 17997?
For Microsoft Outlook 2011 for Mac error code 17997, users often experience an issue where emails fail to send, even though the Exchange Server connection appears active and incoming messages work just fine. This error typically shows up with the message: “Unexpected data was encountered”, and outgoing emails remain stuck in the Outbox. If you check the error log, you may also see messages like “Mail could not be sent” or error code -17997 when attempting to send emails through an Exchange account.
In this blog, we’ll explore common causes of this error and provide effective solutions to resolve it.
Symptoms You May Notice with Error Code 17997
Below are some commonly reported scenarios in which users may see error 17997:
- “Unexpected Data was Encountered – Error -17997” appears when connecting Outlook 2011 for Mac to an Exchange Server.
- Users can successfully receive emails, but sent emails get stuck in the Outbox.
- Sending fails, and Outlook shows the error code -17997 with a message about unexpected data.
How to Resolve Microsoft Outlook 2011 for Mac Error Code 17997?
One can try the following methods to resolve Outlook Mac Error Code 17997.
Way 1: Modify Server Settings in Outlook 2011
To resolve this error, follow the steps below carefully:
- Replace the server name with the full URL that you use to access OWA (Outlook Web App) in your browser.
- Go into the account settings within Outlook 2011.
- Confirm the port configuration. If it’s using the default, update the port number to 442.
This simple change often resolves the sending issue associated with error code 17997 in Microsoft Outlook 2011 for Mac.
Way 2: Rebuild the Server’s Virtual Directories
If updating Outlook settings doesn’t fix the issue, another effective solution is to rebuild the virtual directories on your Exchange Server. To do this, you’ll first need to upgrade your Exchange Management Console to Service Pack 3 (SP3). Once done, you can proceed to reset the directories.
Steps to Rebuild Virtual Directories on Exchange Server
Resetting a virtual directory removes the existing configuration and creates a new one with default settings. Be aware that after resetting, you will need to reconfigure the new directory as per your environment needs.
Resetting the Client Access Server Virtual Directory
Note: Make sure you have the necessary administrative permissions before proceeding.
1: Launch Exchange Management Console
- Open Exchange Management Console
- Navigate to Server Configuration > Client Access
- Right-click on the appropriate Client Access server name
2: Select Virtual Directory to Reset
- Click on Reset Virtual Directory
- Use the Browse option to select which virtual directory to reset. The following are usually available: Autodiscover (Default Web Site), EWS (Default Web Site), ECP (Default Web Site), Microsoft-Server-ActiveSync (Default Web Site), OWA (Default Web Site), and OAB (Default Web Site).
3: Add Directory for Reset
- Once selected, click Next to add it to the reset list.
4: Choose Log File Location
- Click Browse to set the destination for the log file
- The log will contain current settings of the virtual directory (useful for reconfiguration)
- By default, it saves to the Documents folder of the Client Access Server
5: Reset the Directory
- Click on Reset
- Then click Finish
6: Restart IIS
- Run the following command in Command Prompt: iisreset /noforce
Tip: Use Exchange Shell for Advanced Reset
You can also reset virtual directories using the Exchange Management Shell. The exact cmdlets will vary depending on the specific directory you’re resetting.
If the Issue Persists: Create a New Outlook Identity
If rebuilding the virtual directory didn’t resolve the problem, you may need to create a new Outlook identity:
- First, ensure all mailbox data is synced properly.
- Export the mailbox to a .olm file.
- Create a new default identity in Outlook.
- Import the previously saved .olm file into the new identity.
Note: Sometimes, you may need to create a new identity more than once if the issue persists the first time.
Simplify the Process with CubexSoft OLM Converter
If the above manual solutions don’t resolve the issue or you find the process too technical or time-consuming, you can use a professional utility like OLM Converter for Mac and Windows.
This tool is designed for both Mac and Windows OS and helps users to:
Export and convert Outlook Mac OLM files to various formats (OLM to PST, PDF, EML, HTML, DOC, MBOX, ICS, vCard, RTF, MSG, Thunderbird, Gmail, IMAP, Exchange Server, Office 365, etc.)
Easily move mailbox data from Mac Outlook to other platforms
Preserve original folder hierarchy and ensure complete email integrity
Handle large, corrupted, or encrypted OLM files without data loss
User-friendly interface designed for both home and technical users
Supports selective conversion to save time and storage space
Offers a free demo version to evaluate all features before purchase
Whether you’re troubleshooting Outlook Mac Error Code 17997 or simply want to back up or migrate your data, OLM File Converter offers a quick and user-friendly solution.
Conclusion
To summarize, you can fix MS Outlook Mac Error Code 17997 by either:
- Accessing your mailbox through OWA in the browser, or
- Rebuilding the virtual directories on the Exchange Server.
Both methods have been proven effective depending on your specific environment and configuration.
