Recipient mappings are a useful way to ensure that:
- All email remains replyable to, post-migration, even after a Full (Delta) Migration has occurred when performing a tenant to tenant migration while keeping the same domain name, or when changing domain names from Source to Destination.
- Calendar ownership and display name match on the Destination when performing a tenant to tenant migration while keeping the same domain name, or when changing domain names from Source to Destination.
- If a user name is changing, recipient mapping can also be used to rewrite message headers of the emails during migration to the Destination.
Note: If you are using recipient mapping while migrating from one Source domain to multiple Destination domains, a project is required for each Destination domain.
User Prefix Changes:
If a user SMTP address is changing during the migration, Recipient Mapping can be used to ensure that message headers are rewritten with the new prefix. An example is if email@example.com was changing to firstname.lastname@example.org. This is common during mergers, when migrating data to an existing Office 365 tenant and there are user name conflicts.
The following explains how to add a user prefix Recipient Mappings to your project’s Advanced Options.
Under Support/Support Options:
- Recipient Mapping should be added into each project under Advanced Options/Support Options.
- Note that Recipient Mapping changes are made according to the order that the mappings are added to the Support Options. Ensure that the prefix mappings are at the top of the Advanced Options list so they are performed first and not superseded by the action of a domain level recipient mapping option, e.g., RecipientMapping="@abc.com->@xyz.com". Changes are made based on mappings added from the top down. Therefore, ensure that Recipient Mappings are noted in the correct order you wish them to be performed.
- If you have multiple projects in progress for the same migration (e.g., batches), make sure that these mappings are also in the other project.
- The SMTP rewrite is performed by MigrationWiz during the migration process. The Source and Destination SMTP addresses for the mailboxes in the project are simply to define the Source and Destination matching. It does not correlate to any changes made to email headers during the migration. This is why recipient mapping is mandatory; it ensures replyability.
Note: Using the AutoRemapMigratingUser=1 option is not recommended, due to inefficiencies that will mean migrations are slowed down. It is better to use the RecipientMapping= switches to perform the translations.
Refer to How do I add support options to a project or to a single item? for instructions on how to add this support option at either the project or individual item level.
For more information about adding Recipient Mappings to a project, read this article: How do I add recipient mapping to a project?