Reject on Accept rule - SMTP transparent proxy - Failed to connect to SMTP server

[mmisupport]

We are having some trouble passing smtp traffic to our mail server with this weird reject on an accept rule. Are we missing something important here ? 

[PhoneBoy]

The log card says pretty clearly that it couldn't contact the SMTP server.
That would explain the reject.
Also, from the screenshot, it looks like you're using an unsupported version of gateway software (R77.x or earlier) and you should upgrade.

[mmisupport]

Thanks for the reply,

Unfortunately I cant upgrade cause my license is expired.

I can see the 'failure to connect' but I was wondering if the rejected connection is somehow related to my configuration.

So you suggest that the server did not respond or some other middle point cuts off the communication?

Is it necessary to  declare the server as an Mail server?

thanks for your time