Resolving Undeliverable Messages for a Recreated or Migrated Mailbox

When a mailbox is recreated or migrated the system sees it as a “new” address – though the email address has not changed the system ID has.

If you reply to a mail from a user sent prior to the change it will be returned as undeliverable. To avoid this remove the user from the To, CC or BCC lines and then use the To (CC or BCC) buttons to select the user. This will ensure your are using the “new” mailbox.

Another issue has to do with AutoComplete in Outlook. Please complete these steps for any user whose mailbox was recreated or migrated.


Here are instructions for both:

To ensure delivery to a user whose mailbox was recreated or migrated, please adhere to these guidelines:

  1. When replying to an email with one of these users on it sent prior to migration, select them using the “To” button - see below
  2. Remove the migrated users from your autocomplete (even if the address looks correct) – see below

 To select the correct user:

  1. Click the To or CC button
  2. Under Address Book at the top of the screen, select the entry with “AL” in the name (e.g. Growing-MossAL)
  3. Find and select the user in the list
  4. Click the To, CC or BCC button depending on where you want the recipient

 To remove an autocomplete entry:

 Open a new mail

  1. Begin typing the user’s address
  2. When the AutoComplete entries display, click the X next to the one to remove.
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