Migration Manager Directory Synchronization Agent will match the source and target objects according to the attributes selected for object matching, this setting can be found in the Migration Manager Console | right click on the Domain Pair | Properties | Object Matching
The Match target objects by dialog box displays the fixed list of attributes that can be used to match source and target objects.
These attributes are:
1. Account name — If the account names of the source and target object are the same, the objects will be matched.
2. E-mail — For mail-enabled objects, if a source and target object have the same primary SMTP address, the objects will be matched.
3 SIDHistory — If the SIDHistory attribute of an object from one directory contains the security identifier (SID) of an object from another, the objects will be matched.
Select the attributes you want to use for matching the source and target objects. Matching will be performed in top-down priority. To change the attribute priority, use the up and down arrow buttons. When two objects are matched, the information about matching is written to the service attribute specified to store the matching information.