cannot connect Outlook or login to OWA

Check this article for your reference:
http://blogs.microsoft.co.il/yuval14/2012/03/21/exception-type-microsoftexchangedatastoragestoragetransientexception-may-appear-during-logon-to-user-mailbox-in-exchange-2010/

1. It is possible that the mailboxes have been quarantined on the exchange database.
2. Check event viewer application log for more errors.
3. Verify to see if there are no database or disk issues on server.

Is this issue happening to all users or only specific mailboxes????

1) Exchange version ?
2) Single mailbox or all of them ?
3) Detail error? It give exception  which can help further.

Ok the user can now login to OWA but we cannot connect Exchange, this self healed to this point so I have not mad any changes.

Its only affecting 1 user on Exchange 2013.

if it's an single machine issue ..so please check the antivirus if any or firewall on the machine if any... disable and test...

all the best

yes its not a single machine, occurs anywhere I try to configure Outlook, also occurs even if I specify the Exchange Server address

What is the size of the mailbox. If the mailbox is hugh in size then there might be some corruption in the mailbox and that is the reason the mailbox is getting quarantined.

Take a backup of the mailbox and move it to another database with specifying -baditemlimit and -acceplargedataloss to remove corruption.

The mailbox is less than 1GB and we can login to OWA with no issues

I have not determined if the mailbox is quarantined yet