Free/Busy not working after mailbox migration to Exchange 2013

Question

I'm in the process of migrating user mailboxes from Exchange 2007 to Exchange 2013
It seems that many of the users (not all) are having problems seeing free/busy once they have been migrated.  If we remove the Outlook profile and recreate it, all is good.  Problem is that this is happening to more and more people.  Everyone
is on Outlook 2010
Test-OutlookWebServices -ClientAccessServer Ex2013 -identity MyName -MailboxCredential $cred    Results in:
 Autodiscover: Outlook Provider Failure
 Exchange Web Services          Failure
 Availability Service           Skipped
 Offline Address Book           Failure
The same if I run that command against the Exchange 2007 server.
What am I doing wrong?

Answer 1

I should have mentioned that.  Yes, OWA works perfectly for the affected users.  Just as deleting their Outlook profile and recreating a new one does.
Results of Get-WebServicesVirtualDirectory:
Identity    : Exch2007Srvr\EWS (Default Web Site)
InternalUrl : https://legacy.company.com/EWS/Exchange.asmx
ExternalUrl : https://legacy.company.com/EWS/Exchange.asmx
Identity    : Exch2013Srvr\EWS (Default Web Site)
InternalUrl : https://mail.company.com/ews/exchange.asmx
ExternalUrl : https://mail.company.com/ews/exchange.asmx
The URL you reference above is actually the site I used to perform migration.
What's interesting (at least to me) is that on my machine I did not have any issues with seeing calendars. The Test E-mail AutoConfiguration (without Guessmart), I get prompted for my password over and over; however, after clicking on cancel I
get:
Attempting URL
https://mail.company.com/autodiscover/autodisconver.xml found through SCP
Autodiscover to
https://mail.company.com/autodiscover/autodisconver.xml starting
GetLastError=0;httpStatus=401
GetLastError=0;httpStatus=401
GetLastError=0;httpStatus=401
GetLastError=0;httpStatus=401
GetLastError=0;httpStatus=401
Autodiscover to 
https://mail.company.com/autodiscover/autodisconver.xml Failed (0x80040413)
Attempting URL 
https://autodiscover.company.com/autodiscover/autodisconver.xml found through SCP
Autodiscover to
https://autodiscover.company.com/autodiscover/autodisconver.xml starting
GetLastError=0; httpStatus=200.
Autodiscover to
https://autodiscover.company.com/autodiscover/autodisconver.xml Failed (0x800C8203)
Autodiscover to https://company.local/autodiscover/autodiscover.xml starting
GetLastError=12029; httpStatus=0
Autodiscover to https://company.local/autodiscover/autodisconver.xml Failed (0x80004005)
Autodiscover to
https://autodiscover.company.local/autodiscover/autodisconver.xml starting
GetLastError=0; httpStatus=0
GetLastError=0; httpStatus=200
Autodiscover to
https://autodiscover.company.local/autodiscover/autodisconver.xml Failed (0x800C8203)
Local autodiscover for company.local starting
Local autodiscover for company.local Failed (0x8004010F)
Redirect check to
https://autodiscover.company.local/autodiscover/autodisconver.xml starting
Redirect check to
https://autodiscover.company.local/autodiscover/autodisconver.xml Failed (0x800C820D)
Srv Record lookup for hydraforce.ads starting
Srv Record lookup for hydraforce.ads Failed(0x8004010F)
However, when I did this on a system that cannot see any calendars, it all works perfectly.
Browsing to
https://autodiscover.hydraforce.com/autodiscover/autodiscover.xml does result in Error Code 600