Email authentication
DMARC and Email Security Services
Email is the most common attack vector for small businesses. SPF, DKIM, and DMARC help protect your domain from spoofing, phishing, and impersonation.
Why Email Authentication Matters
Without email authentication, anyone can send an email that appears to come from your domain. Your clients, vendors, and partners have no way to verify that the message is real. Attackers use this to send phishing emails, fake invoices, and impersonation attacks that look legitimate.
Domain spoofing
Attackers send emails from your domain to your clients and partners. Without DMARC, there is no way to stop this.
Phishing attacks
Spoofed emails trick recipients into clicking links, entering credentials, or wiring money to fraudulent accounts.
Reputation damage
When spoofed emails land in spam or cause harm, your domain reputation suffers. Legitimate emails may stop reaching inboxes.
SPF, DKIM, and DMARC Explained
These three protocols work together to authenticate your email. Here is what each one does in plain language.
SPF (Sender Policy Framework)
SPF is a DNS record that lists the servers authorized to send email for your domain. When a receiving server gets an email from your domain, it checks the SPF record to see if the sending server is on the approved list. If it is not, the email may be flagged or rejected.
DKIM (DomainKeys Identified Mail)
DKIM adds a digital signature to your outgoing email. The receiving server uses a public key published in your DNS to verify that the message was sent by an authorized server and has not been modified in transit. If the signature does not match, the email may be flagged.
DMARC (Domain-based Message Authentication, Reporting, and Conformance)
DMARC ties SPF and DKIM together. It tells receiving servers what to do when an email fails authentication checks: do nothing (p=none), send it to spam (p=quarantine), or reject it entirely (p=reject). DMARC also sends reports back to you so you can see who is sending email from your domain.
What We Review
We review your current email authentication configuration and identify gaps, misconfigurations, and unknown senders.
01
SPF record review
Verify your SPF record includes all legitimate sending services and does not exceed the 10-lookup limit.
02
DKIM record review
Verify DKIM signing is configured and that public keys are published correctly in DNS for all sending services.
03
DMARC record setup or review
Set up a DMARC record if one does not exist. Review the current policy and reporting configuration if one is already in place.
04
Sender identification
Analyze DMARC reports to identify all services and servers sending email from your domain, both legitimate and unauthorized.
05
DMARC monitoring
Set up ongoing DMARC report monitoring so you have continuous visibility into who is sending email from your domain.
06
Unknown sender investigation
Investigate unrecognized senders found in DMARC reports to determine if they are legitimate services or unauthorized use of your domain.
EasyDMARC MSP in the Tecnico Desk stack
Tecnico Desk uses EasyDMARC MSP to help small businesses monitor SPF, DKIM, and DMARC, identify legitimate and unauthorized sending sources, reduce domain spoofing risk, and produce client-ready email authentication reports.
EasyDMARC supports monitoring and reporting. Mailbox security, phishing protection, and incident response remain part of the broader Tecnico Defend managed security service.
What We Set Up or Monitor
DMARC implementation is a gradual process. We start with monitoring and work toward enforcement at a pace that protects your legitimate email delivery.
p=none (monitoring)
Start with a monitoring-only DMARC policy. This collects reports on who is sending email from your domain without affecting email delivery. This phase identifies all legitimate senders.
p=quarantine (soft enforcement)
After confirming all legitimate senders pass authentication, move to quarantine. Emails that fail DMARC checks are sent to spam instead of the inbox.
p=reject (full enforcement)
When appropriate, move to reject. Emails that fail DMARC checks are blocked entirely. This provides the strongest protection against domain spoofing.
Report
Monthly email authentication summary
Receive a monthly summary of your DMARC reports, including sender volumes, authentication pass/fail rates, and any new or unknown senders.
Optional
MTA-STS and TLS-RPT
Where appropriate, we configure MTA-STS to enforce encrypted email transport and TLS-RPT to receive reports on transport security failures.
How DMARC Supports Cyber Insurance Readiness
Many cyber insurance applications now ask specific questions about email authentication. DMARC, SPF, and DKIM configuration directly addresses these requirements.
"Do you have SPF records configured for your email domain?" We review and configure SPF records.
"Do you have DKIM enabled?" We verify DKIM signing is active and keys are published correctly.
"Do you have a DMARC policy?" We set up DMARC and work toward enforcement.
"Do you monitor email authentication?" We provide ongoing DMARC monitoring and monthly reporting.
How DMARC Supports Tecnico Defend
DMARC monitoring and email authentication are included in Tecnico Defend. As part of ongoing security monitoring, we track your email authentication status, alert you to new unauthorized senders, and maintain your DMARC policy over time.
Learn about Tecnico DefendFrequently Asked Questions
What is DMARC?
DMARC is an email authentication protocol that helps prevent domain spoofing and email impersonation. It works with SPF and DKIM to verify that emails sent from your domain are legitimate.
Do I need DMARC?
If your business sends email from its own domain, DMARC helps protect against spoofing. Many cyber insurance applications also ask about email authentication.
How long does DMARC take to implement?
Initial setup can be done in days. Moving from monitoring to enforcement takes weeks or months to avoid disrupting legitimate email.
Is DMARC included in Tecnico Defend?
Yes. DMARC monitoring and email authentication are included in Tecnico Defend.
Protect Your Domain from Email Spoofing
Start with a Security Fit Call to review your email authentication and build a plan to protect your domain.