novaBBS - comp.mail.sendmail - I need help with a "(may be forged)" issue.

I need help with a "(may be forged)" issue.

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https://www.novabbs.com/computers/article-flat.php?id=368&group=comp.mail.sendmail#368

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From: gtay...@tnetconsulting.net (Grant Taylor)
Newsgroups: comp.mail.sendmail
Subject: I need help with a "(may be forged)" issue.
Date: Sat, 22 Jan 2022 15:37:35 -0700
Organization: TNet Consulting
Message-ID: <ssi0v9$p01$1@tncsrv09.home.tnetconsulting.net>
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Injection-Info: tncsrv09.home.tnetconsulting.net; posting-host="alpha.home.tnetconsulting.net:198.18.18.251";
logging-data="25601"; mail-complaints-to="newsmaster@tnetconsulting.net"
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
Thunderbird/78.13.0
X-Mozilla-News-Host: snews://tncsrv09.home.tnetconsulting.net:563
Content-Language: en-US

by: Grant Taylor - Sat, 22 Jan 2022 22:37 UTC

Hi,

I need some help diagnosing why Sendmail 8.15.2 is saying "(may be
forged)" in the HELO / EHLO and "Possibly forged hostname" in response
to RCPT TO.

Dig et al. are able to resolve the names of the connecting IPv6
address(es) without any problems. Adding the entries (compacted and /
or expanded) to the /etc/hosts file doesn't make any difference either.

The sending system has two different IPv6 addresses, both of which the
receiving system is able to resolve to names without a problem. Both
IPs exhibit the same behavior.

IPv4 between the two systems works perfectly fine.

Does anyone have any suggestions beyond the superficial "fix reverse
DNS" that is so common on the Internet?

The two possible IPv6 addresses (from the same system) are:

- 2600:3c00:e000:1e9::8849
- 2600:3c00::f03c:91ff:fe26:8849

--
Grant. . . .
unix || die

Re: I need help with a "(may be forged)" issue.

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From: INVALID_...@esmtp.org (Claus Aßmann)
Newsgroups: comp.mail.sendmail
Subject: Re: I need help with a "(may be forged)" issue.
Date: Sun, 23 Jan 2022 01:47:27 -0500 (EST)
Organization: MGT Consulting
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logging-data="30336"; mail-complaints-to="abuse@misty.com"
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Originator: ca@x2.esmtp.org (Claus Assmann)

by: Claus Aßmann - Sun, 23 Jan 2022 06:47 UTC

Grant Taylor wrote:

> I need some help diagnosing why Sendmail 8.15.2 is saying "(may be

that's a bit old...

Which OS?
If you use Linux, compile with -DHAS_GETHOSTBYNAME2,
see the README file.

--
Note: please read the netiquette before posting. I will almost never
reply to top-postings which include a full copy of the previous
article(s) at the end because it's annoying, shows that the poster
is too lazy to trim his article, and it's wasting the time of all readers.

Re: I need help with a "(may be forged)" issue.

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From: gtay...@tnetconsulting.net (Grant Taylor)
Newsgroups: comp.mail.sendmail
Subject: Re: I need help with a "(may be forged)" issue.
Date: Sun, 23 Jan 2022 11:08:08 -0700
Organization: TNet Consulting
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logging-data="15642"; mail-complaints-to="newsmaster@tnetconsulting.net"
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by: Grant Taylor - Sun, 23 Jan 2022 18:08 UTC

On 1/22/22 11:47 PM, Claus Aßmann wrote:
> that's a bit old...

Indeed.

> Which OS?

Linux.

> If you use Linux, compile with -DHAS_GETHOSTBYNAME2, see the README
> file.

It's currently a mostly stock install from the VPS provider. So
re-compiling is going to be a non-trivial change.

I'll check the README file to see if I can get more background on why
HAS_GETHOSTBYNAME2 is a thing and how it's different.

Thank you Claus.

--
Grant. . . .
unix || die

10.0 times 0.1 is hardly ever 1.0.

computers / comp.mail.sendmail / I need help with a "(may be forged)" issue.

Subject	Author
I need help with a "(may be forged)" issue.	Grant Taylor
Re: I need help with a "(may be forged)" issue.	Claus Aßmann
Re: I need help with a "(may be forged)" issue.	Grant Taylor