Hi Everyone,
We're running Exchange Server 2013, and I'm trying the following on the SMTP:
- Connecting from internal address should allow anonymous sending emails
- Connecting from external address should force authentication if "mail from" is our domain
If I follow all the basic guides out there, I've created a "FrontendTransport" for the relay, which has ip-rules for our internal addresses and "anonymous users" allowed - and that works. When I connect from an internal ip-address it gives me the "relay" name and I can send without logging in.
However, if I untick "Anonymous" at "Default Frontend", everyone connecting requires to authenticate which stops all new incoming emails.
Is it possible to make it force logins only if "mail from:" is our domain? Currently I can telnet to the smtp from any external ip-address and specify "mail from" and "rcpt to" as our domain and the email gets delivered.
Thanks in advance.
Best regards,
Anton