Maintaining External Addresses

If your users often receive mail from outside your organization, or from other systems within your organization, your users' external addresses should be preserved. For example, if your existing system receives e-mail from the Internet, every mailbox in your system has an SMTP address. With proper planning and tools, you can attach SMTP addresses to the migrated mailboxes. If you choose not to preserve these addresses, all users must provide their new addresses to everyone with whom they exchange e-mail.