Mark a single email as spam in three clicks

Open the email you want to mark as spam. At the top of the message, find the toolbar with buttons for Reply, Forward, and other actions. Look for the icon that looks like a stop sign or a circle with a slash through it — this is the Junk button. Click it, then select Junk from the menu that appears. Outlook moves the email to your Junk folder when ready and learns from the action.

If you do not see the Junk button in your toolbar, click the three dots (more actions menu) at the top right of the email. Scroll down until you see Junk, then click it and choose Junk again from the submenu. The result is the same — the email leaves your inbox.

You can also right-click directly on an email in your inbox list without opening it. A context menu appears. Select Junk, then Junk again. This method is faster if you want to mark several emails at once without reading them.

Key Takeaways

  • The Junk button is in the top toolbar of an open email, or in the three-dot menu if your toolbar is simplified.
  • Right-clicking an email in your inbox list lets you mark it as spam without opening it.
  • Marking an email as spam moves it to the Junk folder and teaches Outlook to filter similar messages in the future.
  • You can select multiple emails at once by holding Ctrl (or Cmd on Mac) and clicking each one, then right-click and choose Junk.
  • Emails in the Junk folder stay there for 30 days before Outlook deletes them automatically.

Block the sender so future emails go straight to Junk

Marking one email as spam helps, but blocking the sender prevents their future messages from reaching your inbox at all. Open the spam email, click the Junk button, and this time select Block Sender instead of just Junk. Any email from that address will now go directly to your Junk folder.

If you want to unblock a sender later, go to your Junk folder, find an email from that person, open it, click Junk, and select Never Block Sender. This removes them from your blocked list and their future emails return to your inbox.

Report phishing emails to Microsoft

If the spam email looks like it is trying to trick you into giving up passwords, banking information, or personal details, it is a phishing email. Marking it as spam is not enough — you should report it to Microsoft so they can investigate and protect other users.

Open the suspicious email. Click the Junk button, then select Phishing instead of Junk. A window opens asking you to confirm. Click Report. Microsoft receives your report and uses it to improve their spam filters. The email still goes to your Junk folder.

Do not click any links or read any attachments from a phishing email, even to "unsubscribe" or "confirm your account." These actions can trigger malware or confirm to the sender that your email address is active.

Create rules to automatically send certain emails to Junk

If you receive spam from the same sender repeatedly, or emails with certain words in the subject line, you can set up a rule to handle them automatically. Open any email from that sender or with that pattern. Click the Junk button, then select Block Sender to block that address, or Never Receive Email From This Mailing List if it is a mailing list you no longer want.

For more control, go to the Settings menu (the gear icon at the top right of Outlook). Select View all Outlook settings, then Mail, then Rules. Click Add new rule. You can set conditions like "from [sender address]" or "subject contains [word]" and tell Outlook to move those emails to Junk automatically. This keeps your inbox clean without you having to act on each message.

Check your Junk folder regularly for false positives

Outlook's spam filter is not perfect. Occasionally, legitimate emails end up in your Junk folder by mistake — these are called false positives. Check your Junk folder at least once a week, especially if you are waiting for important messages like receipts, password resets, or notifications from services you use.

If you find a legitimate email in Junk, open it and click the Junk button. Select Not Junk. Outlook moves the email back to your inbox and adjusts its filter so future emails from that sender are less likely to be marked as spam. You can also add the sender to your Contacts to further reduce the chance of their emails being filtered.

Understand what happens to marked emails

When you mark an email as spam, Outlook moves it to your Junk folder. Emails stay in the Junk folder for 30 days, then Outlook deletes them automatically. If you change your mind within those 30 days, you can recover the email by opening the Junk folder, finding it, and clicking Not Junk.

Marking an email as spam does not delete it from the sender's records or stop them from sending you more emails — it only filters future messages from that sender if you have also blocked them. If spam continues after you have blocked the sender, the sender may be using different email addresses. In that case, report the emails as phishing and consider creating a rule to catch emails with certain keywords in the subject line.

Frequently Asked Questions

What is the difference between marking as spam and blocking a sender?

Marking as spam moves one email to your Junk folder. Blocking a sender moves all future emails from that address to Junk automatically. You can mark an email as spam without blocking the sender, but blocking is more effective for repeat offenders.

Can I recover an email I marked as spam by mistake?

Yes, for 30 days. Go to your Junk folder, find the email, open it, click Junk, and select Not Junk. The email returns to your inbox. After 30 days, Outlook deletes it permanently.

Will the sender know I marked their email as spam?

No. Marking an email as spam is private. The sender does not receive any notification. They only know if you unsubscribe from a mailing list or reply to tell them to stop.

What should I do if spam keeps coming from different email addresses?

Create a rule that catches emails by subject line or content instead of sender address. Go to Settings, Mail, Rules, and add a new rule with conditions like "subject contains [spam keyword]". This catches spam from multiple addresses at once.

Is reporting phishing to Microsoft the same as marking as spam?

No. Reporting phishing sends the email to Microsoft for investigation and helps protect other users. Marking as spam only filters it in your account. Always report phishing emails instead of just marking them as spam.