Error: Retrieving the COM class factory for component with CLSID {0006F03A-0000-0000-C000-000000000046}

Question

I have created windows service in .Net 4.5.Service is written to open outlook client. The code written is correct, since I have run in local host. But when I run from IIS Server, the server throws following error on following line of code:

Error retrieving the COM class factory for component with CLSID {0006F03A-0000-0000-C000-000000000046} failed due to the following error: 0x80040154 Class not registered

I tried the following solutions:

IIS Server > Advanced Settings > Enable 32 Bit APP = true & Identity=Windows

Many Thanks

Answer 1

The IIS runs in a low privilege mode, I believe it is NETWORK SERVICE. This account is restricted heavily from using client-related COM objects, and Outlook client is registered under the respective user account. Technically, you change the (COM configuration)[https://docs.microsoft.com/en-us/windows/desktop/com/hkey-local-machine-software-microsoft-ole], but you should not do it.

Office objects, including Outlook, require a logged user session. With Outlook in particular, it requires a logged user who also has a registered Outlook profile, and an Exchange license (if applicable).

In your case, when you run it from the local host, you have such a session - yours. When you run it on IIS, this session is not available.

What you want to do if officially not supported and is greatly discouraged.