How to Keep Your Microsoft 365 Email Safe - A Simple Guide for Small Businesses

Email keeps your business running - but it’s also one of the biggest ways scammers try to get in. Fake invoices, phishing links, and “spoofed” emails (messages pretending to be from your company) can trick customers and harm your reputation.

If you’re using Microsoft 365 , you already have solid security in place — but to really protect your brand, there are three simple settings every small business should have: SPF, DKIM, and DMARC .

Here’s what they mean, and why they matter.

1. SPF: The Email Bouncer

SPF (Sender Policy Framework) works like a bouncer at the door — it checks if the email really came from an approved source before letting it through.

If someone tries to send an email using your domain but from a dodgy server, SPF will flag or block it.

In short: SPF stops hackers from sending fake emails that look like they’re from you.

2. DKIM: Your Digital Signature

DKIM (DomainKeys Identified Mail) is like signing each email with a secret digital signature. It proves the message came from your domain and hasn’t been changed on its way to the recipient.

In short: DKIM adds trust and helps your genuine emails avoid spam filters.

3. DMARC: The Rule Enforcer

DMARC (Domain-based Message Authentication, Reporting & Conformance) ties SPF and DKIM together.

It tells receiving mail servers what to do if an email fails the checks — whether to allow it, mark it as spam, or reject it entirely.

In short: DMARC helps you stop fake emails and shows you who’s trying to impersonate your business.

4. Why It Matters

Setting up SPF, DKIM, and DMARC gives you real peace of mind:

• Protects your brand from spoofing and scams
• Keeps your emails out of spam folders
• Shows who’s pretending to send emails as you
• Prevents costly fraud and protects your reputation

5. How to Set It Up

You can add these settings in your domain provider’s control panel (GoDaddy, 123 Reg, etc.) or ask your IT support to help.

Start with:

1. Add Microsoft’s SPF record
2. Turn on DKIM signing in Microsoft 365
3. Create a DMARC policy (begin with p=none to monitor, then tighten later)

It only takes a few minutes — and it’s one of the easiest ways to boost your security.

At FOS.net, We’ve Got You Covered

Here at FOS.net , when we onboard a new client, we make sure SPF, DKIM , and DMARC are all set up and tested as standard - because secure email should never be optional.

If you’re not sure whether your business has these protections in place, ask your IT support company if they’ve configured them, and if they haven’t, it’s time they did.

Final Tip

Once everything’s set up, check your configuration using a free tool like MXToolbox

A few small tweaks today can make a big difference - protecting your business, your customers, and your good name.