The following error messages or non-delivery reports:

  • Outlook in Cached Mode
    Your message did not reach some or all of the intended recipients.

    Permission Error 2
  • Outlook in Non-Cached Mode
    You do not have the permission to send on behalf of the specified user.

    Permission Error 1
  • OWA
    You don't have permission to send messages from this mailbox.

    OWA Error

indicate that Send As permissions either haven't been granted, are propagating or a cached entry in Outlook is preventing you from sending as another address.

To fix the issue, perform the following steps:

  1. Double-check if you have Send As permissions on the mailbox / Distribution List you are sending from. Read the Knowledge Base articles on How Do I Enable Send As Or Full Access Permissions On Exchange Account? and How To Send Emails As A Distribution List for instructions.
    Note: it may take up to 2 hours for Send As permissions to propagate.
  2. If permissions are correct on the server, you should no longer receive the error in OWA or Outlook in Non-Cached Mode. Outlook in Cached Mode might still not work due to incorrect cached entries. Make sure that the correct address is chosen from Global Address List.
    Note: the mailbox / Distribution List cannot be hidden from GAL.

    Other Email AddressGAL Lookup