Fix Issue Unexpected Data was Encountered Outlook 2011 Error Code 17997

Nowadays, Outlook has become the preference of most users as it offers various beneficial features to the users. One such feature is offline usage of mail data, for this user need to connect with Exchange Server. It makes easy for them to access their email without internet connectivity. However, user sometimes receives an error message “Unexpected data was encountered Outlook 2011 error code 17997” at the time of connecting Mac Outlook 2011 to Exchange Server. If the user checks the error log then, they will notice, “Mail could not be sent” with this error. Even sometimes, users receive an error “Mac Outlook Error Code 17997” on the screen when user sends email from Outlook for Mac. In the following section, we will discuss the reason and solution to fix send or receive error 17997 in Mac Outlook 2011.

Symptoms Behind Occurrence of Error

There is a scenario given below, which takes place when error 17997 occurs while working on Outlook for Mac.

When the user sends or receives an email while connecting MS Outlook 2011 with Exchange Server. At the time of sending email, messages hang in the Outlook with error -17997, unexpected data was encountered.

Technique to Fix Unexpected Data Encountered Outlook 2011 Error Code 17997

Various solutions are discussed below to fix Outlook Mac Error 17997. It will help user send or receive all email messages easily.

Solution 1:

User can fix the error code by following the mentioned instructions:

  1. Change the server name to the URL in a way to utilize OWA via Browser
  2. Check on default port to change port to 422 in Outlook 2011 settings

Solution 2:

There is another solution to resolve the error by rebuilding the Server Virtual Directory on Exchange Server, for this user needs to upgrade Exchange Management console to SP3 and after that user can rebuild virtual directories.

  • Rebuilding Virtual Directories

For rebuilding the virtual directories, user can reset the virtual directory on Exchange Server because when the users reset a virtual directory, then the virtual directory, which is chosen, will be removed and a new virtual directory will be created by default settings. User can follow the following steps to reset virtual directory.

Note: After a reset, users need to reconfigure virtual directory, as new virtual directory will have default settings.

There are some steps mentioned with which user can reset client access server virtual directory.

Step 1: User can follow the mentioned way to reset the client access virtual directories. However, before performing the process users need to have permission.

  • First, open Exchange Management Console on your system
  • Select Server Configuration >> Client Access
  • Choose Server Client Access name and right click on it

Step 2: Now, select browse option in the reset access virtual directory and choose virtual directory name that user needs to reset >> Next. By default, various directories will be listed.

Step 3: After adding the selected directory to the virtual directory list to be reset, click on next option.

Step 4: Browse path and file name to specify the log file >> Next.

Note: User can use the same settings to rebuild virtual directory. By default, all the log files will copy to document folder of Client Access Server.

Step 5: Select the reset button in the reset client access virtual directory >> Finish.

Step 6: Reset the IIS (Internet Information Services) by running the following command, i.e. iireset/noforce on command prompt.


In the above discussion, two solutions are discussed to resolve the issue Unexpected Data was Encountered Outlook 2011 Error Code 17997. Even if the user again gets an error message then user can create a new identity. It may happen that the error will not resolve by creating the identity first time. On that time, they can create a new identity second time and synchronize all user’s mail then, user can export OLM files, as default create a new identity, and import all the OLM file data.

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