I have a client on Exchange 2003 SP2 that I'm migrating to Office 365. I've done many of these in the past including some from Exch2003. I'm unable to get communication to work. I use testexchangeconnectivity.c
om to run an Outlook Connectivity test and got a 443 blocked error (The specified port is either blocked, not listening, or not producing the expected response.). I've run through the RPC/HHTP config again, made sure the 6001-6002 and 6004 ports are open, I installed a third party SSL cert (client previously only used Exchange for internal email). I can browse to https://
<FQDN>/oma and https://
<FQDN>/Exchange for OWA access. I can telnet fine to port 443 from remote hosts. Can anyone give me an idea to look at next?