Problem
You need to delete/recreate a mailbox for some reason (ex: corruption) but cannot have NDR when the user’s mailbox is recreated. If you deleted and recreated without these step, you would run into the following problems
- Mail sent by the user prior to the recreation will have the incorrect Exchange Legacy DN. When people go to reply to mail sent prior to the recreation they will get a NDR. Same for calendar entries/meeting requests etc.
- The address saved in other users NK2 or cached address lists will be wrong and result in NDRs
- The GAL will possibly have the same issue
Solution
- Write down the LegacyExchangeDN value before removing the mailbox. You can do this either using ADSIEDIT.MSC or running the following Cmdlet from EMS:
- Get-Mailbox AWang | fl LegacyExchangeDN
- Open the EMC, find the user and make a note of
- Email addresses and which is the default
- Group Membership
- Full Mailbox Rights
- Send As Mailbox Rights
- Any custom folder permissions within Outlook
- Right click on the mailbox and select Disable
- This will remove the mailbox/exchange info out of the AD object
- This will leave the AD object intact
- Create your new mailbox
- Verify mailflow
- Reapply the settings listed in 2.
- In the email tab of the mailbox properties
- Add a new email address with type X500 and the value you noted in 1.
- Restart the Exchange Transport Service