How to Block Unwanted Senders in Gmail and Outlook 19 min read · Written by Mae R Davis · Updated · Stop spam.
To block a sender in Gmail, open one of their messages, click More next to Reply, and select Block. In Outlook, right click a message from the sender and choose Block, Block Sender, or add the address under Settings, Mail, Junk email. Future messages then go to Spam or Junk automatically.
Blocking a sender tells your email provider to automatically route future messages from that address away from your inbox and into a spam or junk folder.
An email alias service works differently. Instead of blocking a sender after they already have your address, a service like Email Monster gives every signup a separate address, so a single alias can be turned off without touching your Gmail or Outlook filters.
Key facts
- Gmail: use Block to send a sender's messages to Spam automatically, or create a filter to handle a domain, keyword, or phrase.
- Outlook: add a sender or domain to your Blocked senders list, or adjust your Junk Email filter settings.
- Aliases: disabling a single alias stops a sender without adding anything to a block list.
Unwanted email wastes time and can carry phishing attempts. Blocking a sender or filtering a domain keeps messages out of your main view, though it does not stop that sender from reaching you again through a different address.
How do you block a sender in Gmail?
Gmail lets you block a specific sender directly from a message, or build a filter that matches a domain, keyword, or other pattern. Once you block someone, Gmail automatically sends any future email from that address to Spam.
How do you block a specific address in Gmail?
According to Google's Gmail Help, the steps are:
- Open the message from the sender you want to block.
- At the top right, next to Reply, click More.
- Select "Block [sender's name]."
After you block a sender, future emails from them go to Spam. To undo it later, open a message from that sender, click More, and select "Unblock [sender's name]."
How do you view or edit your blocked senders list in Gmail?
- Click the gear icon in the top right, then select "See all settings."
- Open the "Filters and Blocked Addresses" tab.
From there, select an address and click "Unblock selected addresses," or open a message from the sender and choose "Unblock [sender's name]" from the More menu.
How do you create a filter for unwanted senders in Gmail?
Blocking one address at a time is limited. Gmail's filters can act on a sender, a domain, a keyword in the subject line, or a phrase in the message body, then apply an action automatically.
To build one from the search bar: type your criteria into Gmail's search bar, click "Show search options" to refine it, then click "Create filter."
To build one from an existing message: select the message, click More, then choose "Filter messages like these" to prefill the criteria.
Once your criteria are set, choose what Gmail should do: skip the inbox, mark as read, apply a label, or delete automatically. You can review or edit any filter later from the Filters and Blocked Addresses tab.
How do you block a sender in the Gmail app on iPhone, iPad, or Android?
Google publishes separate help pages for Android and iPhone and iPad, and both list the same sequence as the Gmail website, with tap replacing click:
- Open the message from the sender you want to block.
- At the top right, next to Reply, tap More.
- Select "Block [sender's name]."
Future messages from that address go to Spam, the same as on desktop. To unblock someone, repeat the steps and select "Unblock [sender's name]" instead.
How do you block a sender in Outlook?
Outlook moves messages from a blocked sender to the Junk Email folder rather than deleting them outright. A blocked sender can still send you mail, it simply will not appear in your main inbox unless you check Junk. The exact steps depend on which version of Outlook you use.
How do you block a sender in new Outlook for Windows or Outlook on the web?
Go to Settings > Mail > Junk email. Enter the address under Blocked senders, or enter a domain under Blocked domains, then select Add. Select Save to apply the change.
Microsoft notes that new Outlook does not support blocking senders for third party accounts, such as Gmail, Yahoo, or iCloud, connected to it.
How do you block a sender in classic Outlook for Windows?
Right click a message from the sender, then select Block > Block Sender. To manage the list directly, go to the Home tab, select Block in the Delete group, then choose Junk E-mail Options. On the Blocked Senders tab, select Add, enter the address or domain, then select OK.
How do you block a sender in Outlook for Mac?
Select a message from the sender in the message list, then select Block in the toolbar. Outlook adds the address to your blocked senders list and moves future messages to Junk automatically. Microsoft notes that blocking only works for Exchange based accounts, such as Outlook.com or a work account hosted on Exchange, and not for other account types added to Outlook for Mac.
Source: Microsoft Support, Block or unblock senders in Outlook and Microsoft Support, Outlook for Mac.
How many senders can you block in Outlook?
Microsoft's support documentation states you can have up to 10,000 addresses or domains combined across your blocked senders and safe senders lists. If you need to block more than that, blocking whole domains instead of individual addresses uses fewer entries. [Source]
How long does Outlook keep junk and blocked email before deleting it?
Microsoft's current support documentation states that junk email is retained for 30 days before it is automatically deleted and cannot be recovered after that. [Source] That is the figure Microsoft publishes for the Junk Email folder generally; its documentation does not list a separate retention period specifically for classic desktop Outlook connected to Exchange.
Separately, classic Outlook has an option to permanently delete suspected junk email instead of moving it to the Junk Email folder, found under Junk E-mail Options on the Options tab. With that option turned on, matching messages are deleted immediately rather than waiting out the 30 day window. [Source]
How does Email Monster fit alongside Gmail and Outlook blocking?
Gmail and Outlook both react to spam after a sender already has your address. Email Monster works earlier in that process: it gives you aliases on your own subdomain, such as netflix@yourname.eml.monster, so each signup gets a separate address that forwards to your real inbox.
How do you stop spam through an alias instead of blocking?
If an alias starts receiving spam or gets shared without your permission, you can disable that single alias from the Email Monster dashboard. Your other aliases and your real address are unaffected, and you do not need to add anything to a block list in Gmail or Outlook.
Email Monster also includes a digest feature that groups newsletters and other lower priority mail into a single weekly or monthly summary instead of delivering each message as it arrives.
Gmail vs Outlook vs Email Monster: feature comparison
Gmail and Outlook manage spam after it reaches your account. Email Monster's alias system is meant to keep a sender from getting your real address in the first place. The table below summarizes the differences.
| Feature | Gmail | Outlook | Email Monster |
|---|---|---|---|
| Ease of setup | Block from an open message | Block from an open message, or add via Settings | Create an alias instantly |
| Sender blocking | Sends to Spam folder | Redirects to Junk Email folder | Disable the alias completely |
| Domain blocking | Via a filter, not a one click block | Block entire domains | Not applicable, uses aliases instead |
| Privacy protection | Real email address exposed to senders | Real email address exposed to senders | Real email address stays hidden |
| Spam prevention | Reactive, after spam arrives | Reactive, after spam arrives | Proactive, before the sender has your address |
| Email organization | Filters and labels | Rules and categories | Digest feature consolidates lower priority mail |
| Cost | Free | Free with a Microsoft account | Free plan; Premium $2.99 a month or $6.99 a year |
Which approach should you use?
Gmail's filters and Outlook's Blocked senders list both work well for a sender who is already reaching you. Aliases work best before that happens, since a service only ever sees the specific alias you gave it, not your real address. Many people use both: block or filter what is already arriving, and hand out a new alias for anything new.
Spam made up nearly 45% of global email traffic in 2025, according to Kaspersky's annual spam and phishing report, which puts the figure at 44.99%. [Source]
How Email Monster fits
Email Monster gives you unlimited email aliases on your own subdomain, forwarding to your real inbox. The free plan includes 40 emails a month. Premium is $6.99 a year, or $2.99 a month, and adds unlimited emails plus newsletter digests that group lower priority mail into a periodic summary.
FAQs
How can I make sure important emails aren't accidentally marked as spam?
In Gmail, add the sender to your contacts, or create a filter that keeps their messages out of Spam. In Outlook, add the sender to your Safe Senders list, or set up a rule that keeps their messages in your inbox.
It also helps to check your spam or junk folder occasionally. Marking a legitimate email as not spam helps train the filter to recognize similar messages from that sender in the future.
How does blocking in Gmail differ from blocking in Outlook?
Gmail relies mainly on a per sender Block option plus filters, and routes blocked senders to Spam. Outlook's Block Sender option, or its Blocked senders list under Settings, Mail, Junk email, routes blocked senders to the Junk Email folder instead. Functionally the two are similar: neither stops the sender from sending, both just keep future messages out of your main inbox.