Spam emails clutter your inbox, waste your time, and sometimes carry dangerous phishing attempts. Setting up spam filters in Gmail or Outlook can automatically move unwanted messages out of your inbox and keep you safer online.
This guide walks you through the exact steps to configure spam filters on both platforms—whether you’re using a computer, tablet, or smartphone.
What Are Spam Filters?
A spam filter is an automatic system that identifies and blocks unwanted emails before they reach your inbox. Both Gmail and Outlook have built-in spam filters that work in the background, but you can improve their accuracy by teaching them which messages you don’t want to see.
Think of a spam filter like a gatekeeper at your front door. It learns to recognize unwanted visitors and stops them from entering your home.
Why You Should Configure Your Spam Filter
Most email services catch obvious spam automatically, but some junk messages slip through. By manually marking spam and blocking senders, you help your email provider improve its filtering—not just for you, but for everyone who uses the service.
Proper spam filtering also protects you from phishing scams, which often disguise themselves as legitimate messages.
How to Set Up Spam Filters in Gmail
Gmail’s spam filtering is automatic, but you can enhance it by marking spam and blocking specific senders.
Marking an Email as Spam (Gmail)
On your computer:
- Open Gmail and log in
- Find the unwanted email in your inbox (you can select multiple messages)
- Click the “Report Spam” button (it looks like a stop sign with an exclamation mark)
- The message will be moved to your Spam folder automatically
On your smartphone (iPhone or Android):
- Open the Gmail app
- Tap on the unwanted email to open it
- Tap the three dots (More options) in the top-right corner
- Select “Report Spam” from the menu
Blocking a Sender (Gmail)
Blocking a sender ensures all future emails from that address go straight to your Spam folder.
On your computer:
- Open an email from the sender you want to block
- Click the three dots (More options) next to the reply arrow
- Select “Block [sender name]” from the dropdown
- Confirm when prompted
On your smartphone:
- Open the Gmail app and tap on the email
- Tap the three dots in the top-right corner
- Select “Block [sender name]”
Creating Custom Filters (Gmail Advanced)
For more control, you can create filters to automatically handle certain types of emails.
- Open Gmail on your computer
- Click “Show search options” (the filter icon in the search box)
- Enter criteria—like a specific sender’s email address or keywords
- Click “Create filter” at the bottom
- Choose what happens to matching emails (delete, archive, mark as read, etc.)
- Click “Create filter” again to save
For example, you could automatically delete all emails with “Congratulations! You’ve won” in the subject line.
How to Set Up Spam Filters in Outlook
Outlook offers several spam filtering options, including junk email levels, blocked senders lists, and safe senders lists.
Marking an Email as Junk (Outlook)
In Outlook desktop app (classic version):
- Right-click the unwanted email
- Select “Junk” from the menu
- Click “Block Sender” to block future messages and move the current one to Junk
In new Outlook or Outlook.com:
- Select the unwanted email
- Click “Junk” on the toolbar at the top
- Or select “Report Message” → “Junk”
Blocking a Sender (Outlook)
In Outlook desktop app:
- Right-click a message from the sender
- Select “Junk” → “Block Sender”
In new Outlook or Outlook.com:
- Click the gear icon (Settings) at the top of the page
- Select “Mail” → “Junk email”
- Under “Blocked senders and domains,” click “Add blocked sender”
- Enter the email address or domain you want to block
- Click “Add,” then “Save”
Adjusting Junk Email Filter Level (Outlook Desktop)
You can control how aggressive Outlook’s spam filter is.
- Open Outlook desktop app
- Go to the “Home” tab
- In the “Delete” group, click “Junk” → “Junk E-mail Options”
- Choose a filter level:
- Low — Catches only the most obvious spam (recommended for most users)
- High — More aggressive, but may block legitimate emails
- Safe Lists Only — Only allows emails from your Safe Senders list (very restrictive)
- Click “OK” to save
Adding Safe Senders (Outlook Desktop)
A Safe Senders list ensures emails from trusted contacts always reach your inbox.
- Open “Junk E-mail Options” (follow steps above)
- Go to the “Safe Senders” tab
- Click “Add”
- Enter the email address or domain you trust
- Click “OK” after each entry
Tips for Better Spam Filtering
- Check your Spam/Junk folder weekly: Legitimate emails sometimes get caught by mistake.
- Never click “Unsubscribe” in obvious spam: It confirms your email is active and may lead to more spam.
- Report phishing attempts: Both Gmail and Outlook have “Report Phishing” options that help protect others.
- Don’t reply to spam: Responding tells scammers your email is real and monitored.
Pros and Cons of Spam Filters
Cleaner inbox
Automatically removes unwanted messages and reduces clutter.
Better security
Blocks phishing emails and reduces exposure to scams.
Improves over time
Machine learning makes filters more accurate as you use them.
Can block legitimate emails
Occasionally, important messages are mistakenly flagged as spam.
Requires occasional maintenance
You need to check your spam folder periodically and unblock false positives.
Frequently Asked Questions
What happens to emails I mark as spam?
They’re moved to your Spam or Junk folder, where they’re automatically deleted after 30 days (in most email services). Your email provider also uses this data to improve spam filtering for everyone.
Can I recover an email I accidentally marked as spam?
Yes. Go to your Spam or Junk folder, find the email, and mark it as “Not Spam” or move it back to your inbox. Consider adding the sender to your Safe Senders list to prevent it from happening again.
Will blocking a sender stop all spam?
No. Scammers often use different email addresses, so blocking one sender won’t stop all spam. However, it helps reduce repeat offenders and trains your filter to recognize similar patterns.
Should I use the “High” filter level in Outlook?
Only if you’re willing to check your Junk folder regularly. The High setting catches more spam but also increases the chance of blocking legitimate emails. The “Low” setting is usually the best balance.
Final Thoughts
Setting up spam filters takes just a few minutes, but the benefits last for years. A cleaner inbox means less stress, better focus, and fewer opportunities for scammers to trick you.
Start by blocking the most obvious spam senders and marking junk emails as you see them. Over time, your email service will learn your preferences and do most of the work for you—giving you more time to focus on the messages that actually matter.