1. Domain & Email Settings
SPF TXT Record
Standard TXT@
v=spf1 include:_spf.google.com ~all
DKIM CNAME Record
Standard CNAMEsynxmail.ins1._domainkey.example.com
dkim.synxmail.in
DMARC TXT Record
Standard TXT_dmarc.example.com
v=DMARC1; p=none; rua=mailto:[email protected]
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Explore SynxWeb Email API →Understanding Email Authentication: SPF, DKIM, and DMARC
To prevent spam and spoofing, modern receiving servers (like Google Gmail, Microsoft Outlook, and Yahoo) require domains sending transactional alerts to pass rigorous authentication audits. If your SPF, DKIM, or DMARC alignments are misconfigured, your system notifications—such as OTPs, order invoices, and account confirmations—will be routed directly to the spam folder.
Sender Policy Framework (SPF)
An SPF record is a TXT record stored in your domain's DNS settings. It specifies exactly which servers and IP blocks are allowed to send mail on behalf of your domain. Having multiple SPF records violates RFC standards and causes immediate authentication failure. You must combine all sources into a single TXT record, as demonstrated in our configurator.
DomainKeys Identified Mail (DKIM)
DKIM adds a cryptographic signature to email headers. This signature is verified using a public key published in your domain's DNS. DKIM guarantees that the email's content was not tampered with in transit. SynxWeb recommends using 2048-bit DKIM keys to ensure maximum security standards.
DMARC Alignment
DMARC ties SPF and DKIM together. It instructs recipient systems how to handle messages that fail authentication. Start with a monitoring policy (p=none) to collect XML aggregate reports (via the rua tag) to trace all sending servers. Once verified, elevate the security policy to p=quarantine or p=reject to eliminate brand impersonation.