I am migrating from Exchange 2007 to O365 via Exchange 2013 Hybrid. The Exchange 2013 install was successful, the Hybrid Configuration was successful.
Most mailboxes still exist on Exchange 2007. Some test ones are located on Exchange 2013, and we have migrated several over to O365. All of these have worked with no issues.
OWA and OWA redirect to legacy works, A/S works.
During the build of Exchange 2013, the virtual directories were set to the well-know URL (mail.xxx.com) The Exchange 2007 server virtual directories were set to legacy.xxx.com.
Free/Busy from O365 to Exchange 2013 mailboxes (and Exchange 2013 to O365) work perfectly.
Free/Busy from Exchange 2013 to Exchange 2007 mailboxes get the "hash marks" for free/busy
Free/Busy from O365 to Exchange 2007 mailboxes get the "hash marks" for free/busy
Free/Busy from Exchange 2007 to both Exchange 2013 and O365 work correctly.
I ran the Free/Busy tool from Test Exchange Connectivity and got this error from ANY mailbox querying against Exchange 2007.
Thanks in advance...