The following error occurs when migrating a mailbox from Lotus Domino into Microsoft Exchange using Notes Migrator for Exchange:
"Unable to open mailbox for user <USER@domain>"
This error typically occurs for one of the following 3 reasons:
1. The user-list file supplied to Notes Migrator for Exchange does not contain the appropriate TargetAddress. The value in this column is used to search the target system for the appropriate account. As a result, the TargetAddress listed for each user must match a valid SMTP address in the target account on the Exchange Server.
2. There is an issue with the Windows Message Subsystem on the computer. This error indicates that Outlook is not completely or properly installed on the migration server. To resolve this error, run "fixmapi.exe" from a cmd prompt on the machine. If fixmapi.exe does not resolve the issue, reinstall Outlook on the computer.
3. The Outlook profile on the computer running Notes Migrator for Exchange is not prompting for login credentials. Confirm/verify that the profile is configured to prompt for credentials.
If none of the above resolves the issue then reinstall Outlook on the computer.
NOTE: The user-list file in version 3.1 is saved and read in a tsv (tab-separated values) data format. In pre-3.1 versions, the user-list file is in a csv (comma-separated values) data format.