Logon Failure: The target account name is incorrect while connecting to exchange

Hi,

I have a custom sharepoint timer job that pulls the emails of a specific user acoount and adds to a SharePoint list. Earlier it used to work fine by pulling all the emails.

Now, there has been a change in Excahnge OWA Url,  so I changed that Url in the code and when I do debugging it is throwing me an error:

"Unable to automatically step into the server, Connecting to the server machine 'owa-na.internal.mydomain.com' failed. Logon Failure: The target account name is incorrect."

I don't know where to look at. Can anybody please suggest me where I need to look and fix it?

Thank you very much in advance.

Thanks, Hitchs