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Questions tagged [dmarc]

Domain-based Message Authentication, Reporting, and Conformance (DMARC) is a mechanism by which the owner of a domain uses specially formed DNS records to express domain-level policies and preferences for email validation, disposition, and reporting.

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correct order for Postfix milters

I use the following milters with Postfix: ClamAV, OpenDKIM, OpenDMARC, Rspamd This is also the order they are being called via smtpd_milters. What would be the best order for them regarding performance, resources and spam protection?
basbebe
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How can you tell the difference between rua and ruf DMARC reports?

I have a client that's receiving DMARC reports from various providers however the reports indicate that all checks 'PASS' and all DMARC/DKIM/SPF checking tools indicate the DMARC records are fine. The reports are in XML format and zipped up. Is…
user315851
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Only enable SRS when forwarding to enable DMARC

I am setting up a mail server on my VPS and in order to prevent spam and being marked as spam I have enabled SPF, DKIM and DMARC. However, I do not want to host my own mailbox, so I forward the incoming mail to external mail accounts, e.g. Gmail.…
Matthijs Steen
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DMARC is blocking email that seems like it should be allowed

This is the DMARC record we have set v=DMARC1; p=reject; rua=mailto:[redacted]@coinbase.com; adkim=r; aspf=s So we are rejecting any not match with SPF strictly, and DKIM is relaxed. Here is the SPF record: v=spf1 mx ptr include:_spf.google.com…
Brian Armstrong
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How to prevent emails from my domain through mailing lists to be rejected due to DMARC

I operate my own mail server at speedofsoundgaming.com and mwtd.net. I recently added a DMARC record to my domain to help prevent spam, and once seeing that things seemed to be working, upped the level to quarantine from none. However, I had not…
Michael Taboada
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DMARC fail, but DKIM and SPF are passing

I am using AWS SES (in sandbox mode) to send an email to a GMail address. Unfortunately it gets flagged as spam. Google is nice enough to tell me in the message details that it is a DMARC failure I read the official documentation :…
YannP
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Email server: Remove rua from DMARC DNS entry or stop receiving DMARC reports

I have the following DNS entry for one of my clients email servers: _dmarc IN TXT "v=DMARC1; p=none; rua=mailto:postmaster@example.com" This is the only email server I'm administering, which has a DMARC DNS entry - in other cases SPF and DKIM was…
manifestor
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Using DMARC techniques to block Backscatter

We run a small email (receiving not bulk sending) service (~ 300 domains or so) for our customers and are just starting to introduce DMARC. One of the reasons for doing so is to help stop backscatter (NDRs for emails that weren't sent) by helping…
Rob Lambden
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Why use DMARC when SPF -all can do the job?

With DMARC I can set the policy to rejct mail. But isn’t it the same I can do with -all from within a SPF? Same goes for quarantine and a softfail ~all. Beside the reporting where is the benefit using DMARC on top of SPF?
Gordo2019
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SPF and DKIM pass, but DMARC fails for source_ip

I have configured our DMARC policy to quarantine and our domain SPF and DKIM are configured appropriately. The SPF record is as follows: v=spf1 +a +mx +include:sendgrid.net -all However this is the report being returned: …
Reado
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Postfix setup with different domain name, reverse lookup and SPF

I would like to set up Postfix properly to serve multiple virtual domains while complying to all standards and being able to enable security measures like SPF. The server has the hostname server.domain.tld. Postfix has mydomain set to…
StackExchange42
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What format are DMARC dates?

I have a DMARC report that includes: 1500249600 1500335999 How do I convert the dates to something human?
Greg Pagendam-Turner
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How do I respond to DMARC Forensic Reports

I have just received a DMARC forensic report from Hotmail/Microsoft. My SPF policy seems to have successfully blocked the offending email. I have also blocked the offending IP using IPTables (just in case they try another way). Is there anything…
user6122771
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Interpreting a DMARC report that seems to have conflicting data

I recently implemented DMARC in monitoring mode, in order to begin preparing all the domains I manage. Here is the aggregate report for yesterday. I don't understand why DKIM would evaluate to false under policy_evaluated when DKIM is marked pass…
samh
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SPF and DKIM help: Do the FAIL reports from DMARC indicate an issue?

I am having trouble determining if my SPF and DKIM are configured properly. Here are key details: My domain is mysteryscience.com We send mail from google apps, from SendGrid, and from Intercom. All seem to be working properly, although I do hear…
Keith Schacht
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