The PRS is forgiving when it comes to matching the default field names in the Mail Data but you may want to change the name to something completely different. This may be necessary, for example, if the incoming Mail Data uses different names which you have not control over.
To change a field name you need to add an entry to the [MailDataNames] section in the prs_data.ini configuration file (the prs_data.ini file resides in the Shared Data Folder which is specified on the File Locations page on the PRS Tools->Options dialog) formatted like:
<custom name>=<field name>
Where <custom name> is the field name you want to use and <field name> is one of the default Mail Data field names. For example, putting this entry in the [MailDataNames] section in the prs_data.ini configuration file will ensure Mail Data Comments fields will be saved as Personnel Notes:
[MailDataNames]
Comments=PersonnelNote
NOTE: Be careful not to use a custom name that is already taken.