How does Migration Manager handle merging scenarios when Contacts and mail enabled users match (27811)

In some situations source and target Exchange environments have mail enabled users and Contacts that have the same primary SMTP address. How does QMM handle this types of scenarios where Contact on one side has the same Email address as mail enabled user on the other side? Can contact be merged with the user?

Please refer to the resolution section for the detailed explanation.

QMM in its default configuration without any customization can only handle merging of the same types of objects. There are only two scenarios where Contact on the target side can be deleted in favor of conflicting user (Contact) object provided that "Merge objects with corresponding Contacts" option is selected on DSA properties. But target always contains matching object of the same type as the source. User is matched to a User, Contact to a Contact, Group to a Group etc.

Scenario 1.

Contact on the source has mail enabled user on the target with the same SMTP address reflected in the Exchange GAL (Global Address List) (ProxyAddresses attribute)

1. Migration session.
When migrating objects none of the Exchange attributes (mail, mailnickname, any of the "msExch" attributes) are getting populated. The conflict by "Name" attribute will only occur if migrating to the same OU where the conflicting user account resides. This session will fail. In other scenarios Contact object will be created on the target AD. It will not have Email address and will not be reflected in the target organization Exchange GAL.

2. Synchronization session.
Depending on what OU is specified for the new objects creation it will lead to the same results as #1 because of the conflict in either "Name" or "ProxyAddresses" attributes.

Scenario 2.

Mail enabled user on the source has Contact on the target with the same SMTP address reflected in the Exchange GAL (Global Address List) (ProxyAddresses attribute)

1. Migration session.
When migrating objects none of the Exchange attributes (mail, mailnickname, any of the "msExch" attributes) are getting populated. The conflict by "Name" attribute will only occur if migrating to the same OU where the conflicting Contact resides. This session will fail. In other scenarios User object will be created on the target AD. It will not have Email address and will not be reflected in the target organization Exchange GAL.

2. Synchronization session.
Depending on what OU is specified for the new objects creation it will lead to the same results as #1 because of the conflict in either "Name" or "ProxyAddresses" attributes. If "Merge objects with corresponding Contacts" option is selected on the Synchronization properties the target Contact will be deleted and user object created on the target will be properly mail-enabled and reflected in the target Exchange GAL.
IMPORTANT: Merge is performed based on the TargetAddress value of target Contact and any of the ProxyAddresses on the synchronized user. If Contacts and user are only matching by any of the ProxyAddresses while TargetAddress value is different conflict will be reported and no merge will occur. Please also see the following Quest KB article SOL24845:
How does Migration Manager Directory Synchronization mailbox-enables the target user in Exchange 2000/2003 organizations?
" ... If "Merge objects with corresponding contacts" option is enabled in the User Interface, the target contacts conflicting by"targetaddress" attribute will be deleted. Additionally the LegacyExchangeDN attribute of the contact being deleted is copied to the proxyaddresses of the new object as a secondary x500 address. Membership of the contact is copied to the newly created object."

Scenario 3.

Contact on the source has mail enabled  Contact on the target with the same SMTP address reflected in the Exchange GAL (Global Address List) (ProxyAddresses and TargetAddress attributes)

1. Migration session.
Since contacts don't have samAccountName attribute no matching by Name is possible for the Contacts.  The conflict by "Name" attribute will only occur if migrating to the same OU where the  matching Contact resides. This session will fail. In other scenarios QMM will create  AD Contact object  in the target. It will not have Email addresses and will not be reflected in the target organization Exchange GAL.

2. Synchronization session.
-"Merge objects with corresponding Contacts" option is  NOT selected. Depending on what OU is specified for the new objects creation it will lead to the same results as #1 because of the conflict in either "Name" or "ProxyAddresses" attributes.
-"Merge objects with corresponding Contacts" option is selected.
a) Option of matching by Email address is enabled on the domain pair properties in QMM. Source Contact will get merged into the target corresponding Contact.
b) Option of matching by Email address is NOT enabled on the domain pair properties in QMM. In this case QMM will not be able to match into the target  pre-existing  Contact and will proceed with the new Contact creation. At the conflicts resolution stage  pre-existing target Contact will be deleted and  another  Contact just created on the target will be properly mail-enabled and reflected in the target Exchange GAL. This will look as if the pre-existing Contact was moved from the original OU to the one specified on QMM Synchronization properties for the new objects creation.