Coexistence is ensured by synchronizing the Microsoft Exchange and the Sun platforms. This means that the Sun toolkit treats the coexistence issues up to a certain point, in particular with the following components:
Directory. Can occur as one-way or two-way synchronization for:
Distribution lists and groups
Custom recipients ('LDAP entries' in Microsoft Exchange that point to external mail address that are not part of the Global Address List (GAL))
You can also perform a bulk synchronization of the directory level. You must perform customizations at this level through remapping rules. In addition, the Sun migration tool offers documented APIs to flexibly remap anything that you like to the target Sun LDAP server.
Passwords. The Sun toolkit does not need to change the user password. The toolkit operates “cleanly” on passwords, with no need for users to substitute a new one.
Mail coexistence. The Messaging Server MTA is able to “hook onto” the SMTP flow and copy/forward model to ensure that the Microsoft Exchange mail messages are routed to the new platform.
Calendar free/busy lookups. Coexistence enables users to see the free and busy status of their colleagues, however, only migrated users can view the status of non-migrated users. Non-migrated users are not able to view the free/busy status of migrated users. Nevertheless, experience has shown that the fact that it works for migrated users actually encourages non-migrated users to get migrated.
Public folders. Microsoft Exchange public folders are synchronized with Sun shared folders to ensure that migrated users within a community are sharing the same data between the two platforms.
Calendar synchronization. Unfortunately, performing a full calendar synchronization is almost unrealistic, as there are too many conflicting requirements. For example, not only must you add or delete calendar entries, but you need to inspect each and every property, and there is no notion of “who wins” the reconciliation.