Fix CLS Send or MAPI Mail Error in Email

To fix "CLS SendMail" or Messaging Application Programming Interface (MAPI) email errors, follow the instructions below appropriate for the version of email (Office Outlook , Outlook Express or Windows Mail) that you are using as the default mail handler in Windows. To determine which program is set as the default mail handler in Windows (prior to Vista), open the Windows Control Panel > select Internet Options (under Network and Internet in the Category View) > Programs tab > Email box. You can click the down arrow beside the email box to change the default mail handler in Windows. To set the default mail handler in Windows Vista, click Start > Default Programs > Set your default programs > Select the appropriate program in the list > Select “Set this program as default” > OK.

Office Outlook

Install the Collaboration Data Objects (CDO) feature for your version of Microsoft Office Outlook so that it can process email not created in Microsoft Office. To add (or verify) the CDO feature in Office 2003 (or earlier): insert the Microsoft Office CD in your CD drive > go to Start > Control Panel > Add/Remove Programs > select the appropriate "Microsoft Office" > click the Change button > select "Add or Remove Features" > in Outlook 2003 or later click the Advanced Customization of Applications button (older versions skip this step) > click the plus sign (+) beside "MS Outlook for Windows" > click the down arrow beside the red X in front of Collaborative Data Objects > select Run from my computer > click the Update Now button > click OK. 

Office 2007 no longer includes the Collaboration Data Objects feature code in its default installation. To add Collaboration Data Objects for Office 2007, this feature must be downloaded over the Internet from Microsoft (see "Download Collaboration Data Objects for Office Outlook 2007" in the related articles below).

If removing and re-installing the Collaboration Data Objects (CDO) feature for your MS Office Outlook does not fix its error, go to the Microsoft Office Update web site (http://office.microsoft.com) and download all available updates for Microsoft Office and/or for Office Outlook. Then open Microsoft Outlook, select Help and run "Detect and Repair". Follow the on-screen instructions.

Otherwise, you may try the repair steps in Microsoft's support knowledge base article#813602 (see related article "Repair Microsoft Office Outlook 2003 or 2007 Mapi") reprinted below:

In Windows\System {or Windows\System32}, rename the Mapi32.dll file, and then start the Fixmapi.exe program by:

1. Close all programs.
2. Click Start, and then click Search.
3. Click All files and folders.
4. In the All or part of the file name box, type mapi32.dll, and then click Search.
5. When the search process is complete, right-click the Mapi32.dll file in Windows\System {or Windows\System32}, and then click Rename. (Note: If mapi is in memory, you will not be able to rename it.  Click Ctrl-Alt-Delete and End Task on mapisp32. Verify it's not running before trying to rename it.)
6. Type Mapi32.old, and then press ENTER.
7. Click Start a new search, and then click All files and folders.
8. In the All or part of the file name box, type fixmapi.exe, and then click Search.
9. When the search process is complete, double-click Fixmapi.exe to start the repair process.
10. Follow the on-screen instructions to complete the MAPI repair process for Outlook.