Solve 4 exmerge error opening msg store

I was having an error in my Exmerge log:
“Error Opening Message Store (MSEMS). Verify you have the correct permissions to log on (Unknown Error)”

Techrepublic and Technet did not have an exact solution for me, but I discovered after making enough permissions changes through trial and error on the account on which I was signed on to my exchange server (on which I was running Exmerge from), the exchange admin account, by adding ‘search’ permissions I seemed to give myself the rights I needed to allow me to perform full PST merges from Exchange Mailboxes.

Hope this may of use to others