Server: Windows Server 2008 Standard
Outlook: 2010 & 2003
I am trying to allow various users to "Send As" a different e-mail address. I have enabled "Send As" on the mailbox in questions as well as adding the various users to the "Manage Full Access Permissions" and the "Manage Send As Permissions" as far as I can see I have supplied the users with all the required permissions. I have rebooted the server and when trying to use the "From" option, typing in the e-mail address and sending it, It will always bounce back stating that the permissions are not correct.
I took the users Outlook off "Cached Exchanged Mode" and tried to re-send and that delivered without any problems. This issue appears if using either a Mailbox or Public Folder to store the mail in. However, if I reply to any e-mail for this account, it will reply without any issues. There seems to be an issue with using the "From" option when Outlook is set to "Cached Exchange Mode".
I have applied all the updates to Win Server Standard 2008 and have used Exchange's Best Practice Analyser to check for any updates and still experiencing the issue.
Any ideas on how to resolve this would be greatly appreciated