Think Security helpt met een soepele DMARC-implementatie.
We configureren SPF (Sender Policy Framework) en DKIM (DomainKeys Identified Mail) in DNS, voorzien e-mail servers van DKIM-sleutels en stellen DMARC-beleid in.
Met DMARC Analyzer analyseren we alle DMARC Rapporten, zodat we met zekerheid het DMARC-beleid kunnen aanscherpen voor optimale beveiliging.
Hoe maak je een DMARC record aan?
Of download de whitepaper:
“v=DMARC1; p=reject; rua=mailto:email@example.com; ruf=mailto:firstname.lastname@example.org; fo=1;
V = DMARC protocol version.
P = Apply this policy to email that fails the DMARC check. This policy be set to ‘none’, ‘quarantine’, or ‘reject’. ‘none’ is used to collect the DMARC report and gain insight into the current email flows and their status.
RUA = A list of URIs for ISPs to send XML feedback to. NOTE: this is not a list of email addresses. DMARC requires a list of URIs of the form ‘mailto:email@example.com’.
RUF = A list of URIs for ISPs to send forensic reports to. NOTE: this is not a list of email addresses. DMARC requires a list of URIs of the form ‘mailto:firstname.lastname@example.org’.
RF = The reporting format for forensic reports. This can be either “afrf” or “iodef”.
PCT = The percentage tag instructs ISPs to only apply the DMARC policy to a percentage of failing email’s. “pct=50” will tell receivers to only apply the “p=” policy 50% of the time against emails that fail the DMARC check. NOTE: this will not work for the “none” policy, but only for “quarantine” or “reject” policies.
ADKIM = Specifies the “Alignment Mode” for DKIM signatures and can be either “r” (Relaxed) or “s” (Strict). In Relaxed mode, authenticated DKIM signing domains (d=) that share an Organizational Domain with an emails ‘From’ domain will pass the DMARC check. In Strict mode an exact match is required.
ASPF = Specifies the “Alignment Mode” for SPF and can be either “r” (Relaxed) or “s” (Strict). In Relaxed mode, authenticated SPF domains that share an Organizational Domain with an emails ‘From’ domain will pass the DMARC check. In Strict mode an exact match is required.
SP = This policy should be applied to email from a sub-domain of this domain that fails the DMARC check. Using this tag, domain owners can publish a “wildcard” policy for all subdomains.
FO = Forensic options. Allowed values: “0” to generate reports if both DKIM and SPF fail, “1” to generate reports if either DKIM or SPF fails to produce a DMARC pass result, “d” to generate report if DKIM has failed or “s” if SPF failed.
RI = The reporting interval for how often you would like to receive aggregate XML reports. This is a preference and ISPs could (and most likely will) send the report at different intervals (normally this will be daily).