SMTP server configuration failed

Hi everyone,

I'm trying to configure a SMTP server on my freshly deployed Secure Connect Gateway server.

We have an old SMTP server so :

- no authentication

- TLS1.0

I tried using hostname then IP but I get this error everytime :

"Invalid SMTP details. Re-enter your SMTP server details"

I checked the client TLS setting on my SCG platform which is correct :
"Legacy TLS (1.0/1.1) and TLS 1.2"

Also tried looking in the SCG logs (application.log in secureconnectgateway section) but no more details...

Where can I find the root cause?

Thanks.