/munetakaJupyterHub/Computer/2024/MailServer/WildDuck/79-test_mail_server

§2024-10-01

in order to test my wildduck e-mail server, I sent a mail to my self and here is the details

Received-SPF: softfail (cannot assess local addresses) client-ip=192.168.16.254;
From: =?UTF-8?B?6aC85a6X5L2R?= <alexlai@yushei.net>
To: alexlai@yushei.net
Subject: send a mail to myself
Date: Tue, 01 Oct 2024 05:26:03 +0000
Message-ID: <d521fa22-f585-1e65-35ba-e7030781df5b@yushei.net>
MIME-Version: 1.0
Content-Type: multipart/alternative;
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Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit

Try to find out my wildducl mail server setup.
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Content-Type: text/html; charset=utf-8
Content-Transfer-Encoding: 7bit

<p>Try to find out my wildducl mail server setup.</p>
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ChatGPT said: ChatGPT Based on the email headers you provided, several email authentication mechanisms are at play here, including DKIM, SPF, and DMARC. Here's an explanation of what each does and what the results in your headers mean:

DKIM (DomainKeys Identified Mail) What it does: DKIM allows the domain owner to sign the email with a cryptographic signature. This lets the recipient verify that the email was indeed sent by a legitimate server authorized by the domain owner, and that the email content was not altered in transit.

In your case:

less Copy code dkim=neutral (no key) header.i=@yushei.net header.s=sep2024 header.a=rsa-sha256 header.b=aQGEzihG This means that DKIM was attempted, but it failed with a "neutral" result because no key was found for validation. The header.s=sep2024 indicates that the selector used for the key is "sep2024", and it seems that this key might not be properly set up in your DNS records (or isn't available for verification).

Suggestion: Check the DNS TXT records for your domain to ensure the DKIM public key corresponding to the "sep2024" selector is properly published.

SPF (Sender Policy Framework) What it does: SPF verifies that the email is sent from an IP address authorized by the domain owner. It compares the IP address of the sending server with a list of approved IP addresses defined in the domain's DNS records.

In your case:

bash Copy code spf=softfail (cannot assess local addresses) Received-SPF: softfail (cannot assess local addresses) client-ip=192.168.16.254; The result is "softfail" because the SPF check could not definitively verify the IP address. This might happen because the sending server (192.168.16.254) is a local/private IP address, which would not typically be included in a public SPF record.

Suggestion: Make sure the public-facing IP address of your email server is correctly listed in the SPF record for your domain (DNS TXT record).

DMARC (Domain-based Message Authentication, Reporting, and Conformance) What it does: DMARC builds on DKIM and SPF. It provides a way for email senders to publish policies in DNS that tell receivers what to do if DKIM and SPF checks fail (e.g., reject or quarantine the email).

In your case:

css Copy code dmarc=none header.from=yushei.net; DMARC is not set up for your domain (yushei.net), so no DMARC policy is being enforced. This means there’s no instruction to receiving servers on what to do if DKIM or SPF fail.

Suggestion: Consider setting up a DMARC policy for your domain by adding a DNS TXT record. This will allow you to better protect your domain from email spoofing.

BIMI (Brand Indicators for Message Identification) What it does: BIMI is a newer standard that enables domain owners to display a verified logo next to their email messages. It requires DMARC to be properly set up. In your case: makefile Copy code bimi=skipped (DMARC not enabled) Since DMARC is not enabled, BIMI is skipped. Additional Points: Authentication-Results: This header summarizes the outcome of the various authentication checks. For your email, SPF returned a "softfail", DKIM returned "neutral", DMARC is "none", and BIMI was skipped. TLS Information: Your email is being encrypted in transit using TLS_AES_256_GCM_SHA384, which is a good, secure encryption standard. Conclusion Your email setup seems to have the basics, but there are issues with DKIM, SPF, and DMARC that need to be addressed. Here’s what you can do:

Fix DKIM: Ensure your DKIM key is properly set in DNS with the correct selector ("sep2024"). Fix SPF: Add your server's public IP to the SPF record in your DNS settings. Set up DMARC: Add a DMARC policy to define what actions to take when DKIM and SPF fail. These improvements will make your email system more robust and secure.