Symantec Mail Security for Exchange (SMSMSE) installation says that it "cannot find mailbox"
Error message in smsmse_ExeMonadE2k10_E2k15.log file shows:
< 2019-03-27 08:33:30Z > ExeMonadE2k10_E2k15 : Error: Creating Remote PS Session with Exchange SnapinFailed:
< 2019-03-27 08:33:30Z > ExeMonadE2k10_E2k15 : [server_name] Connecting to remote server failed with the following error message : [ClientAccessServer=SERVERNAME,BackEndServer=server.domain,RequestId=7eaebf6a-d087-4950-be17-32a521b590e0,TimeStamp=3/27/2019 12:33:30 PM] [FailureCategory=Cafe-SendFailure] For more information, see the about_Remote_Troubleshooting Help topic.
Can also appear while trying to verify any user mailbox with Exchange prompt.
This issue can be caused when the Exchange Back End IIS site does not have a proper TLS certificate attached.
Adding my Certificate to the "Exchange Back End" site also worked for me. In my case, I was able to access ECP and OWA (on this server) as well as EMS on other servers.