If your business has its own email domain, attackers can try to forge it, sending scam messages that look like they came from you. Three behind-the-scenes tools, SPF, DKIM, and DMARC, are your best defense.
The problem: anyone can fake your "From" address
Email was designed in a more trusting era. By default, nothing stops a stranger from putting your domain in the "From" line of a message they send. This is called spoofing.
The damage lands on you and your customers:
- Scammers send phishing emails that appear to come from your company.
- Customers, vendors, or staff trust the message because it looks legitimate.
- Your reputation suffers, and your real emails are more likely to be flagged as spam.
To learn how these scams trick people, see our guide on how to spot and avoid phishing.
The solution: three tools that work together
SPF, DKIM, and DMARC are records you add to your domain's settings. Together they let receiving mail servers confirm that a message really came from you and decide what to do if it did not. Here is each one in plain English.
SPF: a list of who is allowed to send
SPF (Sender Policy Framework) is like a guest list for your domain. You publish a record that names the mail servers and services authorized to send email on your behalf, such as your email provider and any marketing tools you use.
When a message arrives, the receiving server checks whether it came from a server on your list. If not, that is a strong sign of a forgery.
DKIM: a tamper-proof signature
DKIM (DomainKeys Identified Mail) adds an invisible digital signature to every message you send. Think of it like a wax seal on a letter.
The receiving server uses a public key published in your domain to check the signature. If it matches, the message genuinely came from your domain and was not altered in transit. If the signature is missing or broken, the message is suspect.
DMARC: the policy and the report
DMARC (Domain-based Message Authentication, Reporting and Conformance) ties the other two together. It does two valuable things:
- Sets a policy. You tell receiving servers what to do with messages that fail the SPF and DKIM checks, such as letting them through, sending them to spam, or rejecting them outright.
- Sends you reports. DMARC can email you summaries showing who is sending mail using your domain, so you can spot both abuse and your own misconfigured services.
A common approach is to start in a monitoring mode, review the reports, and then tighten the policy once you are confident legitimate mail passes.
Why every business with a domain should set these up
If you own a domain, these protections are not optional extras. They are basic hygiene.
- Less spoofing. Forged messages claiming to be from you are far more likely to be blocked.
- Better deliverability. Major email providers favor authenticated senders, so your real emails are more likely to reach the inbox instead of the spam folder.
- Brand protection. You make it much harder for criminals to abuse your good name.
Importantly, these records protect your customers and partners as much as they protect you, because they stop fakes before they ever reach an inbox.
You do not have to do it alone
SPF, DKIM, and DMARC live in technical DNS settings, and a small mistake can accidentally block your own legitimate email. That is the main reason businesses put off setting them up.
The work is straightforward for someone who does it regularly:
- Inventory every service that sends email for your domain.
- Publish correct SPF and DKIM records for each one.
- Add a DMARC record, start in monitoring mode, and review the reports.
- Gradually move to a stricter policy once everything checks out.
How Gecadi can help
Gecadi can set up SPF, DKIM, and DMARC for your domain, verify that your legitimate email still flows, and tighten your policy safely over time. Our team supports homes and businesses on-site in Los Angeles and Orange County and remotely across the U.S., 24/7. Explore our full range of services to keep your email and your brand protected.