Hi Bryan,
I understand that your users using Outlook for Mac 2011 are facing a problem, and I am sorry for any inconvenience that brings.
I have done a test and configured my Office 365 account on a OSX10.9 Mac. It turns out to be working well, and I don’t get any errors.
To narrow down this issue, I’d like to confirm the following information:
1. Do the users using other systems such as Windows encounter any problems?
2. If the issue doesn’t occur before their OSX systems are updated, and only happens after the upgrade, it might be related to the updates. Could you please let one or two affected users rebuild their mail database and try again?
To rebuild the mail database, please refer to http://support.microsoft.com/kb/2360509 .
To rule out the possibility of the account issue, you can also try setting others’ accounts, which have been working well, on these two users’ Outlook clients, then check if the same issue will occur.
Then please let me know the result with more detailed information for our further troubleshooting.
Thanks,
Xinyu Zhou
