How to block spam emails in Gmail, Outlook and on iPhone

Blocking a sender takes a few taps in Gmail, Outlook and the iPhone Mail app. The catch is that most spam doesn't come from the same address twice, so blocking alone rarely ends it. This guide gives the exact steps for each app at the time of writing (November 2026), then explains what to combine blocking with so your inbox actually gets quieter. If you're wondering which provider filters better in the first place, see Gmail vs Outlook spam filter.

Should I block, report or unsubscribe?

Use each tool for a different kind of unwanted mail. Blocking stops one sender. Reporting teaches your provider's filter. Unsubscribing stops a legitimate company you signed up with.

Don't click unsubscribe in outright spam. It can confirm your address is active or lead to a phishing page; see is it safe to unsubscribe from spam. If you're not sure what kind of email you have, spam vs phishing explains the difference.

How do I block spam emails in Gmail?

In Gmail, you block from inside a message. Google says that after you block a sender, "all future emails from them go to Spam" (Gmail Help).

On a computer:

1. Open Gmail and open the message from the sender.
2. At the top right, next to Reply, click More (three dots).
3. Click Block "[sender]".

In the Gmail app on iPhone or iPad:

1. Open the Gmail app and open the message.
2. At the top right, next to Reply, tap More.
3. Tap Block "[sender]".

To report spam (do this as well as, or instead of, blocking): open the email, tap or click More, then Report spam. On a computer you can select several messages and click Report spam at the top. Google says that as you report more spam, "Gmail identifies similar emails as spam more efficiently" (Gmail Help).

To unblock someone: open one of their messages and choose Unblock, or go to Settings > See all settings > Filters and Blocked Addresses, tick the sender and click Unblock selected addresses.

How do I filter spam in Gmail by domain or keyword?

A filter catches messages a block would miss, such as every sender at one domain or every email with a certain phrase.

1. In Gmail on a computer, click Show search options in the search box.
2. Enter your criteria, for example @spammy-example.com in From, or a phrase in Has the words.
3. Click Search to check what matches, then Create filter.
4. Choose an action such as Delete it or Skip the Inbox, then Create filter.

Google notes that a filter set to forward messages only affects new messages (Gmail Help). Keep filters narrow. A filter on a common word can bury real mail.

How do I block spam emails in Outlook?

Microsoft has several versions of Outlook, and the menus differ. Each version moves blocked senders' mail to the Junk Email folder rather than refusing it (Microsoft Support).

New Outlook for Windows, Outlook on the web and Outlook.com:

1. Select Settings > Mail > Junk email.
2. To block one address, enter it under Blocked senders and select Add.
3. To block a whole domain, enter it under Blocked domains and select Add.
4. Select Save.

Classic Outlook for Windows: right-click a message from the sender and choose Block > Block Sender. To add addresses by hand, go to Home > Block > Junk E-mail Options > Blocked Senders > Add. You can enter a full address or a domain such as @example.com.

Limits worth knowing:

• Microsoft says the blocked and safe senders lists hold up to 10,000 addresses or domains. If you need more, block domains instead of individual addresses.
• New Outlook "does not support blocking senders for third-party accounts like Gmail, Yahoo, iCloud". For those accounts, block in the provider's own settings.
• With a Microsoft Exchange account, addresses in your organization's address book are treated as safe and can't be added to the blocked list.

What does Report junk do in Outlook?

For work and school accounts, Outlook's built-in Report button does more than move a message. Select the message, choose Report, then Report junk. Microsoft says the message is moved to the Junk Email folder "and the sender is automatically added to the user's Blocked Senders list" (Microsoft Learn). Report phishing deletes the message. Your IT admin decides whether reports also go to Microsoft, to an internal mailbox, or both, and may have switched the button off.

For more about how Outlook's own junk filter levels and lists work, see Outlook junk email filter settings.

How do I block spam emails on iPhone?

In Apple's Mail app on iPhone, you block a sender from their contact card. Apple's steps at the time of writing (Apple Support):

1. Open the Mail app and open an email from the sender.
2. Tap the sender at the top of the message.
3. Tap View Contact Card.
4. Tap Block this Contact.

Apple says that when you block an email address from Mail, "it goes to the trash folder", and that "email blocking works across all your Apple devices". In iOS 26 and iOS 27, you review the list in Settings > Privacy & Security > Blocked Contacts, where you can also add a contact or unblock one (iPhone User Guide).

To move spam to Junk: while viewing a message, tap the Reply button (curved arrow), then Move to Junk. For several messages, tap Select, tick them, tap the Mark button at the bottom of the list, then Move to Junk (Apple Support).

Apple Mail is only the app. If your Gmail, Outlook.com or work account is set up in it, the service behind it does the real filtering. Block and report in Gmail or Outlook as well, so the block applies wherever you read mail, including on the web.

Using the Gmail or Outlook app on your iPhone instead? Follow the Gmail iPhone steps above, or, with a work or school account, use Report > Report junk in the Outlook for iOS app.

Why does spam keep coming after I block it?

Because a block matches one address or one domain, and most spam is sent from addresses that change with every campaign. Blocking promo@deals-example.com does nothing against offers@deals-example2.net tomorrow. Outlook has a few more reasons a block seems to fail, covered in Outlook blocked senders not working.

What actually reduces spam:

1. Report, don't just block. Reports help the filter recognize the content and pattern, not only the sender.
2. Block domains for persistent senders, not individual addresses, when the domain is clearly junk.
3. Unsubscribe from real companies you once bought from. Much "spam" is legitimate marketing.
4. Don't reply, click or load images in spam. Those actions can confirm your address is live. See is it safe to open a spam email.
5. Use a separate address for shopping and sign-ups, so your main inbox stays private.

The FTC gives the same basic advice: use your provider's filter, mark anything that gets through as spam or junk, and check the junk folder now and then for real mail (FTC). If you keep wondering how they found you in the first place, see where spammers get your email address and why you get so much spam.

Can blocking make things worse?

Rarely, but watch for two traps:

• Blocking a shared domain. Never block gmail.com, outlook.com or your bank's domain because one message from it was spam. You'll lose real mail.
• Blocking instead of reporting phishing. A fake bank or delivery email should be reported as phishing, so it can be taken down. Our guide on how to report a phishing email shows where to send it.

How do businesses block spam for everyone?

Personal block lists don't scale for a business. Every person ends up blocking the same senders, and nobody sees the pattern. Admins have better tools:

• Microsoft 365: the Tenant Allow/Block List blocks a sender or domain for the whole organization. See how to block a sender or domain in Microsoft 365.
• Google Workspace: admins set spam, blocked sender and approved sender rules for everyone. See Gmail spam settings in Google Workspace.
• Filtering before the mailbox: an email filtering service checks mail at the MX level, before it reaches anyone's inbox, and holds suspect messages in a personal quarantine each user can review. Our guide to stopping spam for a whole domain compares the options.

If you look after email for a small team, see how iBlockSpam filters inbound mail for small businesses on Microsoft 365, Google Workspace and other mail servers.

Next steps

1. Report the next spam email instead of only deleting it, in whichever app you use.
2. Block persistent senders by domain in Outlook, or with a filter in Gmail.
3. Unsubscribe from legitimate newsletters you no longer read; report the rest.
4. If a "spam" email might be a scam aimed at you personally, check its headers in the free Email Header Analyzer before acting on it.
5. For a business, move blocking up to the admin level, and consider filtering in front of your mailboxes. iBlockSpam's small business page explains how that works.