Hi Folks We are experiencing issues with Mac Mail (4.2/5.2) when our customers attempt to open up two Exchange 2010 mailboxes or a mailbox of another user. The symptons are varying but mailnly messages don't appear to synchronise, messages get mixed up between accounts and folder lists disappear, also sometimes random messages will sync for no apparent reason. If the user just opens up a single mailbox they are fine. We know this is not an end user issue as two customers have reported this now and we have replicated. It seems as though EWS gets completely confused and starts requesting mail for incorrect mailboxes!!!. This is very strange and we cannot seem to find an answer to this. We are now thinking that TMG is in someway causing issues as we have read that another poster had a similar issue when they accessed their email via Mac Mail behind ISA. I was hoping that someone has either a similar setup that is working or has come across these issues before. I am posting this in the Exchange forum as it is most relevant given all the technologies involved. We also posted in a Mac forum but got NO feedback. Please dont suggest posting somewhere else. We have TMG configured to use FBA using LDAP Pre-Auth with Basic Authentication delegation. Every other non Mac client works fine as well as Outlook 2011 for Mac which is also EWS based. Does anyone have any ideas or would like to attempt to replicate this :) TIA Adam

Hi Adam Just have a try, how about Joining TMG server to domain. Hope it works CheersZi Feng TechNet Community Support

Hi I wish it was as easy as that, not an option I'm afraid. I would love to hear if anyone else is having these issues it seems many people are when trying to open more than one Exchange account and would appear to be an Issue with the the way EWS has been implemented in OSX. One thread mentions that the user fixed this by tricking the client into thinking the accounts were from 2 different Exchange servers by using CNAMEs in DNS!! that just doesn't sound right. TIA Adam

Hi How about following the below article Setup Instructions For MacMail On Snow Leopard Mac OS X http://hosting.intermedia.net/support/kb/default.asp?id=1791 CheersZi Feng TechNet Community Support

Hi Now where did I state that We couldn't set up mac mail? I thank you for your attempt at helping but not really helpful. We can set up mac mail without any issues its when we have more than one account setup that issues are experienced. Its either TMG or a client issue thats the problem we are thinking now. TIA Adam