Re: what error is being reported back to sender, and how to avoid reporting back internal server ports?

[Wietse Venema]

jaso...@mail-central.com:
> 
> 
> On Sat, Apr 9, 2016, at 02:25 PM, jaso...@mail-central.com wrote:
> > I think that's "in postfix".  Looking around to see.
> 
> is the issue of changing
> 
> ... MTA(smtp:[127.0.0.1]:13002) ...

Who cares? No-one can connect to this from outside.
But, if you must, see 

    $ man 5 postconf | less +/'^smtp_reply_filter'

This feature is available in Postfix 2.7.

        Wietse