Hi All,
I know this issue has been posted for a while, but still can't resolved issue. We've new Exchange 2013 SP1 (CU4) installation, everything is working properly, the OWA, Exchange Client Connection, SMTP/POP with SSL, except with SMTP Using Port 25 Non-Encrypted Connection.
If I'm using the SMTP Port 25 without TICK "My Outgoing Server (SMTP) Requires authentication", I've got the error: "550 5.7.1 Unable to relay", but if I TICK the option above, my message will be deliver without any error, how do i get rid this problem, I need to UN-TICK the option above for the time being, since we've hundreds email account, I want to avoid to educate and tell the user and even remote their PC, just to configure this issue, it will drive me crazy, we're going to use the Exchange Client Connection in the future, If everything is smooth and ok.
I research this problem on the Internet and of course with TECHNET, but still can't, anyone can help me on this?
fyi, I tried so many things, delete the default the Default Front End Transport for Port 25, it also not fix my issue.
Thx
Irwan