Hi Yang,
Thanks for your reply. Given that this is Mac Outlook 2011 and has been on going for sometime (more than a good few months) I don't think this is the same issue. However, it would be useful to have confirmation whether the issues listed her: community.office365.com/.../174052.aspx would also affect my OLK2011 users.
Are there any steps that you might recommend I try to test or troubleshoot? I have already created new 2011 identities, re-imaged a mac, rebooted, applied any updates.
regards,
Nick