Some users not receiving email to Outlook client post move to Office 365

Hi, I recently moved one of our clients to Office 365 - most users were able to autodiscover and then send/recv email without issue.  A few users had to be configured manually to connect to office 365 and most of these are now working.  Two users, one autodiscovered and one who had to be manually configured are no longer receiving email though they were initially.  Both users are receiving email to OWA - one is using Outlook 07 and one is using Outlook 10 -- neither are receiving any errors, email is simply no longer delivering.  Any troubleshooting suggestions please?
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Vasil Michev (MVP)Commented:
For starters, recreate the Outlook profile. Start by configuring it in Online mode, that way you will make sure that the size of the mailbox (the local cache of it) is not causing the problem. Other than that, run Outlook in safe mode (hold the CTRL key while launching it or type "outlook /safe" in the run box). Testing from a different network or even different physical location can rule out issues in the network layer on the local environment in general.

Autodiscover is the only supported method, even if you get them configured manually you need to make sure that autodiscover works as expected for features like OOO, MailTips, free/busy lookup, etc.

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t38Author Commented:
Thanks for your input, will test and revert.  Tony
t38Author Commented:
Thanks, deselecting cached mode allows email delivery, however I'd like all users to run in cached mode, why would this be the case
Vasil Michev (MVP)Commented:
Usually it's due to the size of the local profile or profile corruption. Try to reduce the mailbox size by moving older messages to the archive, cleaning up large attachments, etc. After you have brought down the size to something more manageable, create a new profile and configure the mailbox there.
t38Author Commented:
Thanks Vasil, these profiles aren't especially large (approx 2-3GB) whereas one's 6 and more have been fine?
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