Before you attempt to migrate from the Exchange server, create a communication plan to notify users about the new Zimbra email program and to provide users with the new mail access information (Zimbra URL, login name, and password to use).
Zimbra recommends that you plan to perform the migration during off-peak use times. The Exchange server does not need to be stopped in order to migrate accounts. Any emails that are sent to or delivered from Exchange after the account is migrated are not saved in the Zimbra mailbox.
The ZCS Migration Wizard asks you questions in a series of dialog boxes about how to set up the new accounts. Before you start, you should determine:
If your users use the Calendar application, and you are not migrating all users to ZCS at the same time, configure ZCS with the same domain name as used on the Exchange server. When ZCS is configured with the same domain name, a user’s existing email address will be retained when the account migrates to ZCS.
Meeting requests and appointments contain recipient information in the form of email addresses. After migration, if the organizer of an appointment updates an existing appointment or if recipients reply to an invitation, the email address of the original message receives the notification. If the email address has been changed, the notification is not received.
After the accounts are created on the Zimbra server, the email messages, calendar entries, and contact information are imported. You configure the following rules for accounts being imported:
By default, messages larger than 10 MB will not be imported. The message size includes the message and attachments. If the message is larger than 10 MB, a warning is logged to the Migration Wizard log file, which can be reviewed from the
Import Complete dialog when the migration is complete.
