Unable to return a highest UID. This error is caused by a bug in the IMAP implementation used by your email server. Internally, each IMAP message is assigned a unique ID called UID. MigrationWiz retrieves UIDs from the Source server as a way to implement fast data retrieval. Because of the bug in some IMAP implementations, MigrationWiz is unable to retrieve the highest UID from the IMAP server. The highest UID corresponds to the most recent item.
Set an Advanced Option.
MigrationWiz provides an Advanced Option that allows our system to work around certain non-compliance issues. Here are the steps:
- Navigate to your connector.
- Click on Edit Connector.
- Click on Show Advanced Options.
- In the Support Only text field, enter MustUseUidStar=1
- Click on Save, and resubmit your migration.
Upgrade your IMAP server.
Consider upgrading your IMAP server to a version which contains a fix for the bug.
Exclude the folder
If your IMAP server cannot be upgraded, consider excluding the folder.