// email · dmarc
askubuntu.com DMARC Checker
Use this DMARC checker to analyze the email authentication policy for askubuntu.com. DMARC builds on SPF and DKIM to control how receiving servers handle unauthenticated email claiming to come from askubuntu.com.
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DMARC Check for askubuntu.com
The DMARC record for askubuntu.com is published as a DNS TXT record at _dmarc.askubuntu.com. It tells receiving mail servers what to do when an email claiming to be from askubuntu.com fails SPF and DKIM authentication checks — whether to deliver it normally, send it to spam, or reject it entirely.
DMARC also provides askubuntu.com's administrators with visibility into who is sending email using their domain. Through aggregate reports (rua) and forensic reports (ruf), domain owners can monitor authorized and unauthorized email activity.
This DMARC checker shows askubuntu.com's current DMARC policy, alignment settings, and reporting configuration. A well-configured DMARC policy is essential for protecting askubuntu.com from email spoofing and phishing attacks.
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What Is DMARC?
DMARC is an email authentication policy layer that sits on top of SPF and DKIM. While SPF verifies the sending server and DKIM verifies the message hasn't been altered, DMARC ties them together by requiring that at least one of these checks "aligns" with the From header domain.
Without DMARC, even if askubuntu.com has SPF and DKIM configured, receiving servers have no instruction on what to do when authentication fails. DMARC fills this gap by providing an explicit policy (none, quarantine, or reject) and a feedback mechanism through reporting.
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DMARC Policies Explained
DMARC has three policy levels. "p=none" is monitor-only mode — authentication failures are reported but email is delivered normally. This is the recommended starting point for askubuntu.com when first implementing DMARC. "p=quarantine" sends failing emails to the spam/junk folder. "p=reject" blocks them entirely, providing the strongest protection.
The "pct" tag controls what percentage of failing messages the policy applies to, allowing a gradual rollout. For example, askubuntu.com could start with "p=reject; pct=10" to reject only 10% of failing messages while monitoring the impact, then gradually increase to 100%.
Most organizations roll out DMARC in phases: start with "p=none" to gather data, analyze reports to identify all legitimate email sources, add them to SPF/DKIM, then move to "p=quarantine" and finally "p=reject". askubuntu.com's current policy level reveals where it sits in this rollout.
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DMARC Alignment
DMARC requires that either SPF or DKIM "aligns" with the From header domain. For askubuntu.com, this means the SPF-authenticated domain or the DKIM signing domain must match askubuntu.com (or a subdomain of askubuntu.com in relaxed mode).
Alignment can be "strict" (exact domain match only) or "relaxed" (organizational domain match, allowing subdomains). The "aspf" tag controls SPF alignment and "adkim" controls DKIM alignment. Most domains use relaxed alignment (the default) because it's more flexible while still providing good protection.
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Frequently Asked Questions
Does askubuntu.com have DMARC? — The DMARC analysis for askubuntu.com shows whether the domain has a published DMARC record at _dmarc.askubuntu.com. If no record is found, askubuntu.com has not configured a DMARC policy.
What is askubuntu.com's DMARC policy? — The policy level (none, quarantine, or reject) is reported in the DMARC analysis. "reject" provides the strongest protection, while "none" is monitoring-only.
Does askubuntu.com enforce email authentication? — A DMARC policy of "quarantine" or "reject" indicates that askubuntu.com actively enforces email authentication. A policy of "none" means askubuntu.com monitors but doesn't enforce.
How do I set up DMARC for my domain? — Start by creating a TXT record at _dmarc.yourdomain.com with the value "v=DMARC1; p=none; rua=mailto:dmarc-reports@yourdomain.com". Monitor the reports, then gradually increase enforcement to quarantine and reject.