Emails are an essential part of everyday work. They enable quick communication with customers, suppliers, and colleagues. But emails have a security problem: it's technically easy to fake the sender. Criminals exploit this to send messages under false identities. The result: phishing, malware, or fraud attempts. Small businesses are especially affected – often without realizing it.
Without protective measures, anyone can send emails in your name. This leads to a loss of trust, data breaches, or financial damage. This is where SPF, DKIM, and DMARC come in – they ensure that emails truly come from you and are delivered securely.
SPF works like an approved sender list for your domain. You define which servers are allowed to send emails on your behalf. Think of it like an authorized driver list for your company car: only those on the list can drive. Everyone else stays parked.
Advantages:
Protects against simple spoofing
Once set up correctly, it runs automatically
Disadvantages:
Not sufficient on its own
DKIM adds a kind of digital stamp to each of your emails. The recipient can verify whether the message really came from you and if it was altered in transit. It’s like a seal on an envelope: if it’s intact, nothing has been opened or tampered with.
Advantages:
Ensures message integrity
Improves the deliverability of legitimate emails
Disadvantages:
Technically more complex to set up
DMARC combines SPF and DKIM. It specifies what should happen to emails that fail these checks – for example: “reject” or “mark as spam.” At the same time, DMARC generates reports showing who is trying to send emails on your behalf. DMARC is like a bouncer who knows exactly who’s allowed in – and keeps a log of who tried.
Advantages:
Significantly increases protection
Provides transparency on attack attempts
Disadvantages:
Reports are technical and hard to understand without help
Important to Know:
More and more email providers like Gmail, Microsoft, and others now require SPF, DKIM, and DMARC to prevent emails from landing in spam or being rejected. Without these standards, businesses risk that their legitimate messages won’t even reach recipients.
A small agency uses several tools to send emails. Some messages land in customers’ spam folders; others don’t arrive at all. On top of that, the domain is suddenly being used to send fake emails. After a brief investigation, the agency contacts an IT service provider.
The IT partner sets up SPF, DKIM, and DMARC, adjusts the mail server settings, and monitors the DMARC reports regularly. Since then, communication has been reliable and secure. Customers receive the emails, and trust is restored.
Email is one of the most important communication channels in business. But without protection, it’s like an unlocked mailbox that anyone can drop messages into. With SPF, DKIM, and DMARC, you build a solid foundation for secure communication – like a security system for your digital front door.
Especially for small businesses, having a professional IT partner is worthwhile. The technology behind the scenes is complex, but protecting your brand and your customer relationships is priceless.
🔒 Act Now: IT Security Check for Your Emails
Not sure if your emails are well protected? Let’s take a look together. We offer a straightforward IT check specifically for SMEs, sole proprietors, and freelancers.
Contact us for a non-binding consultation – before someone else starts sending emails in your name.
More tips on email security can be found here: Email Security in 2025