The Spark Team
Smart. Focused. Email.
Fast, cross-platform email designed to filter out the noise - so you can focus on what's important.
Definition
💡 Spam: unsolicited bulk email nobody asked for, sent to thousands, sometimes millions, of addresses at once. Sometimes it's just an annoying ad. Sometimes it's a scam wearing an ad's clothing.Spam isn't one thing. It ranges from harmless mass marketing you never signed up for to outright fraud, and almost half of all email sent worldwide falls into this category.
Why spam is still such a massive problem
Open your spam folder right now. However full it looks, that's only the fraction your filter actually caught, not everything that got sent your way.
Kaspersky found that 44.99% of all email sent worldwide in 2025 was spam. Basically every other email on the planet. And that number's been remarkably stable for years, not because filters got worse, but because sending spam costs almost nothing. A spammer needs a list of addresses and a mail server, and they're in business.
Why does it keep working, even after decades of filters getting smarter? Because it doesn't need a high hit rate. Send a million messages and get a 0.1% response, and that's a thousand people who clicked, bought, or handed over information.
Email clients like Spark fight this on the front end. Gatekeeper screens messages from senders you've never emailed before, so unfamiliar senders don't land directly in your inbox unchecked. It catches a different slice of the same problem than your provider's spam filter does: senders you've simply never interacted with before.
Types of spam worth knowing
Not all spam is created equal, and lumping it together hides some real differences.
Bulk commercial spam is the classic version: unsolicited ads for products or deals you never asked about. Annoying, mostly harmless, and the biggest chunk of what actually gets sent.
Phishing spam poses as something legitimate, your bank, a delivery notice, a colleague, to steal credentials or money. Spark's phishing email glossary entry covers the red flags in more depth. This is the category that actually costs people money.
Malware-laden spam hides a payload in an attachment or link, banking on you clicking before thinking.
Greylisting isn't a type of spam, worth clarifying since it comes up in the same conversation constantly. But it's actually a technique mail servers use to fight spam, briefly rejecting messages from unfamiliar senders to see if they retry. Real senders usually do. Spam operations usually don't bother.
Bulk commercial spam is a nuisance. Phishing and malware spam are the ones that actually cost you something.
How to block and report spam
Handling this well takes maybe thirty seconds per message, and the steps are close to identical everywhere you check mail.
In Gmail:
- Select the message, or messages, then click Report spam at the top
- Reported spam gets added to your Spam folder and helps Gmail's filter learn
- Getting legitimate newsletters you don't want anymore? Use Unsubscribe instead of reporting spam. It's faster and doesn't risk flagging a real sender
In Outlook:
- On the web or in new Outlook, go to Settings, then Mail, then Block or allow, and add the sender or domain to your Blocked senders list
- In classic Outlook desktop, use Home, then Junk to mark a message, or Home, then Block, then Junk Email Options to manage your full block and allow lists
In Spark:
- Set Gatekeeper to screen new senders before they land in your inbox, rather than auto-accepting everyone
- Block a sender's entire domain with Command+Option+Shift+B on Mac, or Control+Alt+Shift+B on Windows, which opens Command Center
Reporting spam does more than clean up your own inbox. It's training data. Every report makes the filter slightly sharper for the next person too.
Spam prevention best practices
Never click links in a message you weren't expecting. Hover first, and check where it actually leads.
Use a separate address for signups and freebies. Keep one clean, mostly spam-free address for people who actually matter, and burn a secondary one on every "free ebook" form.
Report instead of just deleting. Deleting clears your inbox. Reporting actually improves the filter.
Don't reply, ever, even to unsubscribe from something sketchy. Replying, or clicking a shady "unsubscribe" link, just confirms your address is active, which gets you more spam.
Check your spam folder occasionally, but don't rescue everything blindly. Most of what lands there earned its spot.
Related terms