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MS Outlook 2011 Mac Error Code 17997

Published By Raj
Debasish Pramanik
Approved By Debasish Pramanik
Published On January 15th, 2024
Reading Time 4 Minutes Reading
Category Email Tips

For offline accessing mail through Outlook on Mac you need to connect it with Exchange Server. However, sometimes you may get the error message “Unexpected data was encountered” while connecting Mac Outlook 2011 to Exchange Server and if you will check the error log you will see “mail could not be sent” with the error code -17997 or “Outlook Mac Error Code 17997” may appear on your screen when you try to send emails from MS Outlook for Mac 2011 Exchange Account.

In this Blog we will discuss some scenarios when user can get this error message and solution to fix Outlook Mac Error Code 17997.


Following are some reported scenario when error 17997 may appear on users screen.

“Unexpected Data was Encountered error Error -17997” while connecting MS Outlook 2011 to Exchange can connect to Exchange server and receive mail, but when sending, the messages hang in the Outbox with error -17997, unexpected data was encountered.

How to Fix Outlook Mac Error Code 17997?

You can try following solution to fix error; Outlook Mac Error Code 17997.

Solution 1

You need to follow below mentioned instructions to fix this error

  • Changed name of the server to the URL in order to access OWA via your Browser.
  • In Outlook 2011 Settings, Make a check on default port and change the Port to 442.

Solution 2

You can also rebuild the Server Virtual Directory on Exchange Server to solve Outlook Mac Error Code 17997, for that you need to upgrade Exchange Management console to SP3 and then rebuild the virtual Directories.

Rebuild the virtual Directories

To rebuild the virtual directories you can reset the virtual directory on an Exchange Server because once you reset a virtual directory, the selected virtual directory will be removed and a new virtual directory will be created with default settings. You can follow below mentioned steps to reset the virtual directory.

Note: You need to reconfigure a virtual directory after its reset because a new virtual directory will have default settings.

Reset Client Access Server Virtual Directory

Step 1: You can follow below mentioned steps to reset Client Access virtual directories. But before performing this procedure you need to be assigned permissions.

  • Open the Exchange Management Console
  • Click on Server Configuration and then Click on Client Access
  • Select the Server Client Access name and then Right Click on it.

Step 2: In Reset Access Virtual Directory, Click on Browse, select the virtual directory name you want to reset and then click on Next. The following virtual directories will be listed by default.

  • Autodiscover (Default Web Site)
  • EWS (Default Web Site)
  • ECP (Default Web Site)
  • Microsoft-Server-ActiveSync (Default Web Site)
  • OWA (default Web Site)
  • OAB (Default Web Site)

Step 3: Once the selected directory is added to the list Virtual directory to be reset then click on Next.

Step 4: Click on Browse to specify path and file name for the log file and then click on Next.

Note: The log file contains the settings of virtual directory that you are about to reset. You can use these settings if you want to rebuild a virtual directory with the same settings. By default, the log files will be copy to the document folder of Client Access Server.

Step 5: In Reset Client Access Virtual Directory, Click on Reset and then click on Finish.

Step 6: Reset Internet Information Services (IIS) by running command iisreset/noforce on command prompt.

You can also reset the Client Access virtual directory by using the shell; however the cmdlets will differ depending on the virtual directory to be reset.

If your problem was not fixed by the above mentioned solutions then you need to create a new identity. It might happen that your problem will not resolved by creating the identity first time. In that case you need to create a new identity second time. Once you sure that you have all user’s mail synced, you need to export .olm file, create a new identity as the default and then import the .olm File.

To end, we can say that user can access the OWA via Browser or rebuild the Virtual directory on an Exchange Server to fix the Outlook Mac Error Code 17997.


By Raj

A technical analyst and a writer with innovative ideas when it comes to technology. Provides solutions, tips and tricks to get things done using technology.