To re-map the merge fields via the Admin Tool, follow these steps.
In the Admin Tool, click Mail Merges.
Drill into the mail merge.
Select View/Edit Merge Fields.
Drag and drop appropriate fields (from the left) to their counterpart on the right.
Click OK, then OK again.
Try running the merge again.
If you've removed fields that were already within an existing mail merge, then the mail merge document will lose its reference fields and will need to be reconfigured and remapped.
You will need to add those missing fields back into the data source of the mail merge, and then map them again using the steps above.
Important Notes
If you are creating a custom mail merge for holiday statistics, especially for leavers, it's important to know that this merge would need to be run after the end date is added to the employee's appointment.
This is because the holiday statistics are calculated using start and end dates, meaning if there is no end date at the point in which you run the mail merge, the absence statistics will pull through at their full values rather than their pro-rated values.
Mail merge that you have created is not working as expected
If you created a mail merge that is not pulling the data as expected and you've followed the above steps to troubleshoot, we recommend getting in touch with your account manager to discuss a plan for our Professional Services team to assist you.