UID FETCH error: Can't fetch that data: This error is caused by a well-known bug in the IMAP implementation used by your email server. This typically affects IMAP servers known as Zimbra email servers. The bug is documented here: http://www.zimbra.com/forums/error-reports/25560-error-sync-uid-fetch-failed-uid-fetch-error-can-t-fetch-data.html.
Internally, each IMAP message is assigned a unique ID (UID). MigrationWiz retrieves UIDs from the Source server as a way to implement fast data retrieval. MigrationWiz also retrieves UIDs from the Destination server as a way to prevent creation of duplicates when performing multi-pass migrations. Because of the bug in some IMAP implementations, MigrationWiz is unable to retrieve UIDs from the IMAP server.
Upgrade Your IMAP Server
Consider upgrading your IMAP server to a version that contains a fix for this well-known bug.
- Sign in to your MigrationWiz account.
- Click Mailbox Migration.
- Locate and edit your Mailbox Project.
- Click Advanced Options.
- Under Support, put a check in the Do not search Destination for duplicates button.
- Click Save.
By disabling the search for duplicates, MigrationWiz stops fetching UIDs from the Destination server. As a result, the error is not encountered. Note that duplicate prevention is still in effect, but only as long as you use the same mailbox object. For example, if you perform multiple migrations using the same MigrationWiz mailbox record, no duplicate will be created. However, we cannot guarantee protection against duplicates if you recreate the MigrationWiz mailbox record.