CM 10.1 email link - account running services

We are currently running CM 10.1, with plans to go to 23.4 next month.

Under the current and previous build, we have been trying to switch the account running the email link services.  The account currently running the services is mine.  With the help of IT, I finally convinced the bill payers that this was a bad idea.  We purchased an additional Administrator license for CM and set u pa new account to run the email link services.  The new account has all the same permissions as my account on the server and, as far as we can tell, in Exchange.  However, whenever we try to switch the account running the email link services, email link fails.

I'm looking for any suggestions as to why the new account is not successfully running the email link services.