For a lot of small business employees in Quebec, it’s the same routine every morning: open Outlook and sort through a dozen emails that have no business being in the inbox. Sketchy promotions, fake invoices, newsletters nobody signed up for. These messages waste time, but worse, they’re often the entry point for phishing and ransomware.

The good news is that Outlook gives you several tools to take back control of your inbox. In this guide, we’ll show you how to block spam and unwanted senders, whether you’re on the desktop app, the web, or mobile, and when it’s time to move to managed protection for your business.

1. Why spam costs your small business money

Spam isn’t just annoying. It’s a real security risk for your business. The vast majority of cyberattacks against small businesses start with an email: a fake delivery notice, a fake payment request, a link that leads to a spoofed page. One click from a busy employee can be enough to compromise an entire network.

Beyond the danger, there’s the hidden cost of wasted time. If every member of your team spends ten minutes a day sorting junk mail, that adds up to hours of lost productivity every week. For a small business in Trois-Rivieres or the Mauricie region running a lean team, that’s far from negligible.

• Risk of phishing and credential theft
• Daily time losses across the whole team
• Cluttered inbox, real messages buried in the noise
• Common entry point for ransomware

2. Block a specific sender in Outlook

The fastest way to stop spam from a known source is to block the sender directly. In the Outlook desktop app on Windows, it takes a few seconds.

1. Right-click the junk email in your message list.
2. In the menu, hover over Junk.
3. Click Block Sender.

The message moves to the Junk Email folder right away, and any future messages from that address will be routed there automatically. You can review and manage your list of blocked senders anytime in your junk email settings, handy if you block an address by mistake and want to remove it.

3. Adjust the junk mail filtering level

Outlook lets you adjust how aggressive its filter is. Depending on how much spam you get, you can choose a stricter or a more relaxed setting.

Open the Home tab, click Junk, then Junk E-mail Options. You’ll find several protection levels, from most permissive to most restrictive. A higher level catches more spam, but keep an eye on your junk folder for the first few days, since real messages can end up there by mistake.

• No automatic filtering: only blocked senders are filtered out.
• Low: catches the most obvious spam.
• High: strict filtering, worth monitoring closely.
• Safe Lists Only: only your trusted contacts reach the inbox.

For businesses that want a structured approach to email security, our managed IT services include advanced filter configuration that goes well beyond what Outlook offers by default.

4. Block an entire domain

Sometimes the problem isn’t a single address, it’s an entire domain. If you’re getting spam from several addresses ending in the same domain name, you can block that whole domain instead of each address one by one.

In Junk E-mail Options, go to the Blocked Senders tab, click Add, and enter the full domain. Every email from that domain will now be treated as junk. This works especially well against spam waves that keep changing sender addresses but stick to the same sending domain.

• Useful against mass spam from a single service.
• Saves you from blocking dozens of individual addresses.
• Use with caution so you don’t accidentally block a legitimate partner.

5. Blocking spam on Outlook web and mobile

Working from a browser or your phone a lot? The same tools are available, just slightly rearranged.

On Outlook web

Open the email, click the three dots at the top right of the message, choose Block, then confirm. The message moves and the sender is added to your block list. You can manage this list in settings, under Mail then Junk email.

On the mobile app

In the Outlook app on iOS or Android, open the message, tap the three dots, then select the option to move it to junk or report it. Reporting also helps Microsoft improve its filters for everyone.

6. When manual blocking isn’t enough

Blocking spam by hand works fine for personal use. But for a business, it’s a never-ending fight: spammers keep changing addresses, spoof legitimate senders, and disguise attacks as credible internal messages. At that point, Outlook’s built-in filter quickly hits its limits.

Managed protection works upstream, before the email even reaches the inbox. It analyzes links, verifies sender authenticity, quarantines suspicious attachments, and applies security rules across the whole organization. This is the kind of protection small businesses in Trois-Rivieres and the Mauricie region are adopting for peace of mind.

• Advanced filtering before the email is delivered.
• Protection against impersonation and targeted phishing.
• Consistent rules for every employee, no individual setup needed.
• Ongoing monitoring and tuning by specialists.

Frequently asked questions

How do I unblock a sender I blocked by mistake in Outlook?

Go to Junk E-mail Options, open the Blocked Senders tab, select the address, and click Remove. The sender will be able to reach you normally again.

Does blocking a sender actually delete their emails?

Not exactly. The messages don’t disappear, they’re redirected to your Junk Email folder instead of the inbox. You can empty that folder regularly or set it to empty automatically.

Why am I still getting spam even though I’ve blocked senders?

Because spammers keep changing addresses and domains. Manual blocking can’t keep up with that pace. A managed email security solution filters threats based on behavior, not just address, which stays far more effective over time.

Protect your small business email in the Mauricie region

Blocking spam in Outlook is a good first step, but real peace of mind comes from a complete security strategy. Our team helps businesses in Trois-Rivieres and across the Mauricie region set up solid, tailored email protection. Check out our IT services for small businesses or reach out directly through our contact page to discuss your needs.