Office 365 Shared Mailbox slow

After trying all of these options with no success – http://support.microsoft.com/kb/2441551/en-us

Add the Shared Mailbox as a separate account to the same Outlook profile.

Optional IT Step

If the mailbox is auto mapped, you may need to remove and re-add the permissions using Exchange Online Powershell with -AutoMapping:$false.

Remove-MailboxPermission SharedMailbox – User user@domain.com – AccessRights FullAccess

Add-MailboxPermission SharedMailbox -User user@domain.com – AccessRights FullAccess -AutoMapping:$false

Next Step

Add the Shared Mailbox to the profile using the Add Account Setup.

Click File > Account Settings > Account Settings…

Select New… Enter the email address of the Shared Mailbox into the “Your Name” and “E-mail Address” textbox.  Click Next.

When prompted for credentials, enter the same credentials as the primary Office 365 mailbox owner.

After the email account is successfully configured, restart Outlook.