Re: [tlug] [slightly OT] SMTP and the internet, protocols and the internet

[Christian Horn <chorn@example.com>]

Hoi Fernando,

On Mon, Jan 11, 2021 at 12:24:07PM +0000, Schwartz, Fernando G. | @SCA wrote:
> 
> Hallo Chris, I often test against < echo@example.com > (use to check
> against " TU-Berlin " as well) and check the return headers. Your setup must
> pass all 4 checks, which include:
> [..]
> --->>>
> Authentication-Results: univie.ac.at;
> 	iprev=pass ( ... ) smtp.remote-ip= ...;
> 	spf=pass smtp.mailfrom= < your domain >;
> 	dkim=pass header.d= < your domain > header.s=mail header.a=rsa-sha256;
> 	dmarc=pass header.from= < your domain >;
> 	arc=none
> --->>>
> 
> Otherwise, it's crazy talk from Deutsch Telco.
> 
> Further, if you check at < https://mxtoolbox.com/diagnostic.aspx >,
> 
> 220 fluxcoil.net ESMTP Postfix (Debian/GNU) is missing a " rDNS " to the IP.
> That's probably the main issue.

Hah, indeed, I had not noticed, good catch!

It's an issue with the hoster, I opened a ticket with them.
t-online also acknowledged via mail that my rDNS is ok.  Their
comments are regarding the other points I mentioned, i.e.
"provide full name and address on your website".

Chris