Hello Eddie,
A simple manual solution to transfer .pst files into an Exchange account is briefly described below.
You can follow these steps easily.
1. Log in to your Exchange account (as administrator).
2. Click on Exchange Server Manager > Target database > Properties > Security
3. Add Exchange Recovery Administrators group and allow full access & control permissions on the database.
4. In Exchange Bin directory > copy the ExMerge setup file & ExMerge.ini file.
5. Now run ExMerge.exe and click Next.
6. Click on Procedure Selection > Extract or Import > Next > Import data into an Exchange Server Mailbox > Next.
7. In Destination Server page > Enter Exchange Server name
8. On Import Procedure > choose any one option: Copy, Merge, Replace.
9. Chose the advanced options to select Folder, Date range and click Next.
10. Microsoft Exchange Mailbox Merge Wizard > Mailbox Selection > choose the file to import.
11. Choose the desired option in Locale Selection > Next.
12. Browse > select folder contains PST files.
13. Click Next > Save Settings option.
14. Hit on Next > when the process gets completed > Finish.
Hope this will help you to solve your issue.
Regards,
Michael