Off topic: smtp HELO question

[RW]

On Mon, 06 Mar 2017 12:34:58 -0500
Quartz wrote:

> > So if your NAT transforms internal addresses to W.X.Y.Z and a
> > reverse lookup 'host W.X.Y.Z' returns 'foo.example.com' then you
> > should configure your mail client to EHLO as 'foo.example.com'  
> 
> OK thanks, that's kinda what I was expecting. Unfortunately for me,
> my external address floats around depending on what my ISP gives me,
> so I can't configure a static name in my client to match that. For
> now I'm trying to see what happens if I set it to the name of my
> domain I own, but the servers that host that aren't the ones I send
> mail through.

Don't bother with this.


> 
> >For mail submission you generally
> > identify yourself by logging into the server after switching your
> > connection to TLS,  
> 
> I do use TLS, but what I'm trying to debug is not so much that the
> email service *I* use checks, but that the final receiving server
> scans through the headers and flags anything with a NAT address. 


It's probably not that. I suggest you try:

 https://www.mail-tester.com/

it may reveal what the problem is, unless it's just a BOFH on the
receiving end doing something very odd.