Best Anti-Spam Tools

Spam has been a nuisance from the moment businesses and consumers started using email accounts. Employees can end up spending a lot of time scanning through inboxes full of unwanted sales promotions and accidentally deleting important business emails that are surrounded by spam entries in the list of unread messages. Anti-spam software has become one of the best weapons against malicious email communications.

Without an anti-spam filter, just one wrong click can place your device and network in danger. Inbound emails are one of the most common entry points for malicious software in enterprise environments.

Here is our list of the best anti-spam software:

  1. Mailwasher EDITOR’S CHOICE A spam blocker for Windows Live Mail, Outlook, Outlook Express, Incredimail, Thunderbird, Gmail, Hotmail, Yahoo, EM Client. Download free tool.
  2. Trustifi Inbound Shield (GET DEMO) This cloud-based email security system scans incoming mails and roots out malware and spam – ideal for medium-sized businesses and enterprises (50+ seats min requirement). You can register for the demo.
  3. Hornetsecurity Email Spam Filter and Malware Protection Service This cloud-based system filters out spam and phishing emails and also blocks malware and DDoS attacks.
  4. SpamTitan A web-based email spam filter that covers Microsoft Office 365.
  5. SpamSieve The best email spam filter for Macs with adaptive spam identification over time.
  6. Comodo Dome Antispam An edge email spam blocking service.
  7. MX Guarddog A spam filter that also blocks DDOS attacks, phishing attacks, malware, and viruses.
  8. SPAMfighter A spam filter for Outlook, Outlook Express, Windows Live Mail, Windows Mail, and Thunderbird.
  9. ORF Fusion A spam filter with a 23-layered testing system.
  10. Zerospam This cloud-based solution works autonomously, looking for keywords and specific file types to block spam, phishing, and malware.

The best anti-spam software blockers

Our methodology for selecting anti-spam software

We reviewed the market for anti-spam software and analyzed the options based on the following criteria:

  • An anti-spam system that integrates into email services
  • Automatic spam blocking
  • Customizable filtering rules
  • Malware blocking
  • An event log
  • A free assessment period or money-back guarantee
  • Value for money with a suitable set of tools for a good price

1. Mailwasher (FREE TOOL)

MailWasher Pro screenshot

Mailwasher is a program that is used to block spam before it reaches your inbox. The tool is compatible with all email providers on desktop and mobile devices. Email providers supported by Mailwasher include Outlook, Outlook Express, Incredimail, Thunderbird, Windows Live Mail, Gmail, Hotmail, Yahoo, EM Client, and more. The diverse range of email accounts supported by Mailwasher makes the software versatile in enterprise environments.

Key Features

  • Pre-filters mail offsite
  • Integrates with major email clients
  • Content filtering

Why do we recommend it?

Mailwasher is a proxy service that intercepts emails and blocks spam and malware while passing through all other emails. This service integrates with a lot more email services that the other options on this list and that includes Webmail systems.

To stop viruses from entering your inbox, the program allows you to preview and delete emails before they are downloaded to your computer. By blocking emails like this you can view information within the email without opening it and leaving your computer at risk of transmitting a virus.

Filtering is another way that Mailwasher monitors incoming emails for suspicious signs. The filter can spot spam content and offensive words so that the sender can be automatically blacklisted from future correspondence. To stop false alerts you can add colleagues and clients to your ‘friends’ list.

Who is it recommended for?

Mailwasher is a good choice for any business. Small businesses can access Mailwasher Free, which only protects one email account but it is possible to sign up for several accounts.


  • Available for all major mail applications such as Gmail, Hotmail, and Yahoo, making it a flexible option for home users using a third-party mail service
  • Can scan and delete malicious attachments before they reach the inbox
  • Can filter for offensive content, good option for protecting children with email addresses
  • Comes free with paid version


  • Interface is outdated and difficult to navigate with large amounts of events
  • Not the best fit for enterprise networks or large businesses
  • Expensive when compared to similar tools

There are two versions of Mailwasher available to download: Mailwasher Free and Mailwasher Pro. Mailwasher Free is available free of charge and supports one email address. MailWasher Pro starts from $49.95 (£37.71) and supports multiple email addresses with support seven days a week.

Mailwasher Download 100% FREE Tool

2. Trustifi Inbound Shield (ACCESS DEMO)


Trustifi Inbound Shield is a cloud-based email protection system that you implement in your own mail server through an API. Adding on this plug-in sets up a call to the remote process to scan each incoming mail. The service is also available as a plug-in for Microsoft 365 and Google Workspace.

Key Features:

  • Cloud-based
  • Doesn’t require architectural changes to install
  • Admins can review quarantined items – minimizes end-user disruption

Why do we recommend it?

Trustifi is a very effective spam filter. However, there are many tools on this list that match that description. The advantage that this tool has over its rivals is that it is very easy to implement. The service is delivered as a plug-in for all of the major email systems, including those that are cloud-based, such as Microsoft Exchange and Gmail.

The Trustifi system is able to spot spam, phishing emails, and bulk emails that are termed “graymail.” The system uses a combination of AI-based threat detection and email address and IP address blacklists. It looks at source email addresses and correlates them to known identifies of employees to block impersonation attempts. It can also detect malicious links to impersonating or infected websites.

Trustifi Inbound Shield slots into your Google Workspaces and Microsoft 365 accounts to offer protection for your email system that expands beyond spam filtering. This security service uses AI to identify phishing attempts and will also look for mismatches in source domains and IP addresses to identify masquerading. This system will also scan emails and attachments for viruses.

Who is it recommended for?

Medium-sized businesses through to large enterprises would mostly benefit from using Trustifi. The system can be set up by any administrator who is able to manage a mail server, so you don’t need exceptional technical skills to install and manage this service.


  • A plug-in for email servers
  • Integrations with Microsoft 365 and Google Workspace
  • Pre-filtering


  • Would prefer a free trial

As well as scanning the email header and body, Trustifi Inbound Shield checks through attachments. What the system does with suspicious emails is up to you. The system presents a range of options that can be configured to coordinate with your security policy. When suspicious emails are detected, they can be quarantined for manual inspection. The system will notify the administrator when malicious mails are detected and compile reports on detection rates and outcomes. In order to discover the price for Trustifi Inbound Shield, you need to request a quote. You can access a demo.

Trustifi Inbound Shield Get DEMO

3. Hornetsecurity Email Spam Filter and Malware Protection Service

ZEROSPAM screenshot

Hornetsecurity Email Spam Filter and Malware Protection Service is a cloud-based system that stands between your email server and the rest of the world. It will filter out phishing, spam, malicious links, and malware and it also blocks DDoS attacks. The service checks outgoing emails as well. For further protection, the program uses TLS encryption to keep your interactions safe from snooping. In the event the client-server goes down, the tool will use automatic mail queuing to help you return to normal operations ASAP.

Key Features

  • Edge service
  • Ransomware protection
  • Phishing detection

Why do we recommend it?

Hornetsecurity Email Spam Filter and Malware Protection Service doesn’t link into your mail system as a plug-in. Instead, it acts as a proxy, pre-filtering emails before forwarding clean emails to your mail server. Hornetsecurity offers a service availability guarantee of 99.99 percent uptime.

Hornetsecurity has a 99 percent success rate in blocking spam. Infomails are also blocked but held in quarantine, offering you the option to download them. It strikes a balance between screening out harmful messages without blocking communications from legitimate email users. From an enterprise perspective, this is an anti-spam platform that doesn’t get in the way of day-to-day operations.

Who is it recommended for?

As it also checks outgoing emails, Hornetsecurityy offers a data loss protection system built into its email filtering service. This makes the tool a very good choice for businesses that need to comply with sensitive data protection standards.


  • Runs in the cloud, no need for onboarding or complex installation
  • Provides complex routing to serve multiple domains and email servers
  • Anti-spam has a low false-positive rate, helping avoid lost business-related emails to the spam filter


  • Could use better management features for multiple inboxes

The Hornetsecurity service is able to operate for multiple email servers and can also serve multiple domains per client. The service queue mail if your own email server becomes unavailable. This means that even if something goes down, your service stays available when you need it.

4. SpamTitan

TitanHQ SpamTitan Screenshot

SpamTitan is a web-based anti-spam solution intended for Microsoft Office 365 accounts. The tool is designed to discover phishing email attacks, spear-phishing attacks, and zero-day attacks. To recognize the latest threats SpamTitan uses a mixture of machine learning and Bayesian analysis to identify new attacks. The powerful email protection against zero-day threats is excellent for minimizing exposure towards emerging email threats.

Key Features

  • Compliments Microsoft 365
  • AI-processes for spam detection
  • Blacklisting and whitelisting
  • Manually identify major targets

Why do we recommend it?

SpamTitan implements AI-based detection that scans through the contents of each email and looks for anomalies, such as address spoofing. The tool can build up its own blacklist for a specific client company but the company doesn’t deploy a global blacklist like N-able Mail Assure.

IP address whitelisting and blacklisting controls whether mail reaches your inbox or gets blocked from future communication. For wider security, you can apply different degrees of Spam Confidence Levels to users, user groups, and domains. By segmenting your email environment in this fashion you can manage potential entry points much more effectively.

Who is it recommended for?

SpamTitan is a cloud-based system, so you don’t need to have technical skills to install it. The system plugs into Microsoft 365, so it will monitor all of the Outlook mailboxes for your users. However, the SpamTitan system isn’t available for any other email system. The minimum number of email accounts this service will cover is 25, so it isn’t suitable for very small businesses.


  • Built specifically for Office 365 users, making it an attractive option for 365 mail systems
  • Uses AI and behavioral analytics to detect and stop threats
  • Allows for manual prioritization of threats


  • Interface feels outdated and can be difficult to navigate
  • Outlook plugin may cause Outlook to open slowly or crash
  • Logs could be easier to manage and parse

Prices are levied as a subscription with a rate per user per month. There is a minimum order of 25 user licenses. The price per user per month lowers if you choose a longer payment cycle. The options range from a monthly payment to a 3-year payment plan. The lowest price comes with the 3-year plan, which works out at $1.49 (£1.12) per user per month. However, you have to pay for the whole payment period in advance, so that 3-year option for 25 users works out at an upfront payment of $1,336,50 (£1008.95). You can try SpamTitan on a 14-day free trial.


5. SpamSieve


The spam filter in Mail on Macs isn’t very good. If you use a different email client, you are stuck with whatever Junk main identification that system provides. However, if you want a better spam filtering service, you can try SpamSieve instead.

Key Features

  • Runs on Macs
  • AI-based spam detection
  • Blacklistingt and whitelisting

Why do we recommend it?

SpamSieve is specifically designed to operate on the native email system for Macs and other email clients that run on macOS. This tool is very easy to install because it is offered as a plug-in. The system builds up a whitelist and a blacklist over time to finetune blocking for your regular activity.

This spam filtering solution includes whitelisting and blacklisting and it uses machine learning to improve spam identification in your Inbox over time. You can set up your own block list and also customize other features of the interface, such as its color and layout. SpamSieve also allows you to create your own mailbox management scripts that perform different actions depending on factors such as the sender or subject line.

SpamSieve works as a plug-in so you can access its functions from within your email client instead of needing to go to a different application. It will work with a long list of email systems on Macs, including Apple Mail (, Airmail, Entourage, MailMate, Mailsmith, Postbox 5, PowerMail, and Outlook.

Who is it recommended for?

As it only runs on Macs, this tool is suitable for businesses that only have Macs on site. The pricing structure means that you can get a license for just one Mac or many, which means that it is a scaleable service that is easy to expand as a small business grows. Large organizations get bulk discounts.


  • Operates within your existing email client
  • Applies machine learning to improve and tailor spam identification
  • Allows customization through settings and scripts
  • Includes whitelisting as well as blacklisting


  • Not free forever

A single-user license costs $30 (£22.65) per year and you can also get a two user license, called the Family plan, for $48 ($36.24). A site-wide plan is priced on consultation. SpamSieve is available for a 30-day free trial.

6. Comodo Dome Antispam

Comodo Dome anti spam screenshot

Comodo Dome Antispam is a spam prevention tool designed for enterprise users. Comodo Dome Antispam scans and filters emails to keep your inbox safe from cyber attackers. When downloading files from the inbox, Comodo Dome Antispam uses its Valkyrie file verdict platform to analyze files as they are being downloaded. You can open and interact with a file without any risk of infection even from the latest malware attacks.

Key Features

  • Choice of self-hosted, private cloud, or SaaS service
  • Sandboxing for attachments
  • Pre-filters spam before the mail server

Why do we recommend it?

Comodo Dome Antispam offers the option of a hosted SaaS package or a downloadable software package, so it competes with every other system on this list. The tool provides file scanning for attachments, phishing detection, spam filtering, malicious link blocking, and malware detection.

Email filtering controls the type of messages you see when you open up your email account. Emails with viruses are blocked so you don’t get put offline to make sure you have complete transparency over emails sent to your inbox. Through the management console, you can view archived and quarantined emails.

Who is it recommended for?

The deployment options of Comodo Dome Antispam give it a very wide market. Comodo has a menu of highly-regarded cybersecurity tools and existing customers of Comodo will be particularly attracted to the anti-spam system.


  • Analyzes files as they are downloaded for threats, and before they arrive in the inbox
  • Advanced filtering can junk or sort emails based on keywords, sender, or size
  • Available as an on-premise or cloud-based solution


  • Interface feels like it hasn’t been updated since its launch in the 90s
  • Emails can be delayed if misconfigured

There are three installations of Comodo Dome Antispam available: Shared Server, Hosted Cloud, and On-Site. To view the pricing, you need to contact the company directly. If you’re looking for an anti-spam solution with flexible deployment options, Comodo Dome Antispam is highly recommended and you can assess it with a 30-day free trial.

7. MX Guarddog

MX Guarddog

MX Guarddog is a spam blocker that uses TLS encryption to protect your email inbox. Phishing attacks, malware, DDoS attacks, and viruses are just some of the things that MX Guarddog defends against. Once any communication is blocked, you can view a quarantine report which will show the message content that was blocked.

Key Features

  • Blocks spam and malware
  • SaaS package hosted in the cloud
  • Integrates with access rights managers

Why do we recommend it?

MX Guarddog operates as a proxy service that receives your emails, filters them, and then passes on the good ones. It blocks malware, spam, phishing attempts, and DDoS attacks. The system is a good continuity service, too because it stores up emails if your own mail server goes offline and delivers them when it comes back.

Legitimate mail is forwarded straight to your email server. MX Guarddog automatically syncs email addresses from Windows AD, LDAP, and cPanel systems for convenience. In the event that your server goes down, your mail will be stored and automatically delivered to you the next time you’re online.

Who is it recommended for?

MX Guarddog is affordable and has a rate per email address, so it is accessible to businesses of all sizes.


  • Better interface than similar solutions
  • Can easily remove false positives from quarantine
  • Can integrate and sync with LDAP and Active Directory services, good for Windows-based email systems
  • Protects against phishing as well as file-based malware


  • Interface feels like it hasn’t been updated since its launch in the 90s
  • Emails can be delayed if misconfigured
  • Charges per email, which makes budgeting unpredictable

MX Guarddog is a great low-cost alternative for stopping spam in its tracks. The tool operates as a SaaS package and starts at a price of $0.25 (£0.20) per email address, per month. There is no charge for user or domain aliases. The service is available on a one-month free trial.

8. SPAMfighter


SPAMfighter is a spam filter compatible with Outlook, Outlook Express, Thunderbird, Windows Mail, and Windows Live Mail. SPAMfighter’sfiltering works in multiple languages and can block spam in English, Spanish, German, French, Italian, Polish, Danish, and more. Once a suspicious email has been flagged the software will add the sender to the blacklist and block future emails from reaching your inbox.

Key Features

  • Plug-in for major email clients
  • Free version available
  • Maintains local blacklist

Why do we recommend it?

The SPAMfighter system works on a crowdsourced intelligence model. When a user receives an email and marks it as spam, the source email address and IP address get flagged. If enough users flag the same source, it gets added to the global blacklist.

The user interface is simple to navigate and you can view live statistics on blocked messages. In addition, you also have Spam Abuse Reporting at the click of a button if you need to gather information. Being able to organize all of this security information helps to make sure that you know about everything that is trying to reach out to your account.

Who is it recommended for?

Home users will definitely want to try the free SPAMfighter. For businesses, the reliance on enough people reporting a spam email campaign might seem a little weak. However, the system has more than 8 million users, so it should be able to catch most spam campaigns.


  • Supports multiple languages, good for international use
  • Can view live statistics on emails such as volume, spam ratio, and number of blocked spam attempts
  • Can forward spam that gets through so the system can learn to identify it in the future


  • Dated interface is hard to navigate and learn

Apart from the free SPAMfighter for home use, there are three business options: SPAMfighter Mail Gateway, which installs on Windows, SPAM fighter Hosted Mail Gateway, which is a SaaS version, and SPAMfighter Exchange Module, which is a special plug-in for Microsoft Exchange Server. You can access any of the business packages with a 30-day free trial.

9. ORF Fusion

ORF Fusion

ORF Fusion is a piece of spam filter software designed specifically for business use cases. The tool eliminates false positives and ensures that legitimate email makes its way to your inbox. One of the unique selling points of ORF Fusion is that it has 23 layered tests to check the status of mail. These tests are a mixture of blacklist and whitelist tests that stop malicious mail without affecting genuine mail.

Key Features

  • Integrates with mail servers
  • Administrator controls over spam handling
  • Blacklisting and whitelisting

Why do we recommend it?

ORF Fusion is a software package that runs on Windows. It is specifically designed to integrate with Exchange Server and IIS SMTP server. This tool operates through a blacklisting mechanism to which, over time, are added whitelisted addresses. The balance between acceptable and banned email addresses is interlinked with a series of other scans and checks on each arriving email.

You can create your own whitelists to make sure that your trusted email senders aren’t put through spam filtering. The user also has control over what happens to those emails that are caught by the spam filter. For instance, you can bounce them to reject the transmission, keep the mail, or redirect it to a different mailbox.

Who is it recommended for?

You would need to be running your business on Windows Server and have your email system operated by Exchange Server to benefit from the ORF Fusion package. Pricing is charged per year according to the number of email accounts covered by the software with the minimum number of accounts being 10.


  • Very advanced, built for email administrations
  • Offers detailed blacklisting by IP address, IP range, country, and DNS
  • Email passed through 23 different filters before being allows to the inbox
  • Highly configurable


  • Higher learning curve than similar software
  • Designed for professionals, not built for the non-technical
  • Misconfiguration could lead to delayed emails and false positives

Overall, ORF Fusion’s low false-positive rate makes it ideal for enterprises looking for information security that doesn’t impede their ability to communicate. ORF Fusion integrates with Microsoft Exchange and the IIS SMTP Service. The price of the product starts at $55 (£43.75) per year for 10 users. ORF Fusion is available for a 42-day free trial and buyers get a 90-day money-back guarantee.

10. Zerospam


Zerospam operates as a proxy based in the cloud. It catches all of your incoming emails and assesses each message before forwarding the safe emails on to your email server. The tool quarantines all suspicious emails, so they can still be checked and approved manually.

Key Features

  • Cloud-based solution
  • Uses machine learning
  • Keyword searches

Why do we recommend it?

Zerospam claims to block 98.99 percent of all spam. This could be due to an overzealous policy. However, the administrator will loosen the detection process over time. Some blocked emails might be valid and as you approve them, the system alters its blocking algorithm, which leads to a more accurate assessment for future emails.

The tool will block Trojans and other malware in attachments and identify links to suspicious sites easily. However, identifying spam and phishing attempts is a lot more complicated. The Zerospam system uses a machine learning method to adapt its blocking system.

The Zerospam policy requires administrator input in the first few weeks of operation. This can be time-consuming. However, it is the only way that a business can get a truly tailored spam filter that properly adapts to the regular pattern of email activity that the company expects to receive.

Who is it recommended for?

Zerospam offers a very reasonable price, which makes it appealing to businesses of all sizes. Its method of channeling all inbound emails means you save a lot of space on your own servers and infections won’t be able to get anywhere near your own system. This is a particularly good option for businesses that run virtual offices with a dispersed, home-based workforce.


  • Reduces traffic on your network
  • Email archiving option
  • Scaleable pricing


  • Very large systems require custom pricing

Zerospam is based in Italy and the company sets its subscription price in Euros. This is 5 Euros ($5.44/£4.39) per month to cover five mailboxes or 10 Euros ($10.88/£8.78) per month to protect up to 1,000 mailboxes. There is also a Premium plan that adds on email archiving and costs 20 Euros ($21.76/£17.56) per month for 1,000 mailboxes. You can get a 30-day free trial to test the Zerospam system.

Best anti-spam software

There is so much variety amongst anti-spam software providers that it can be difficult to choose. If you’re unsure you can’t go wrong with a tool like N-able Mail Assure or SpamTitan. Both tools are easy to use with whitelisting and blacklisting to control what mail reaches your inbox.

Email spam blocker software FAQs

Is scanning outbound emails important?

There are two important reasons to scan outgoing email. The first is to prevent spam emails from being sent from addresses on your domain. This is a reputation management issue because a high volume of spam will get all of the emails sent from your domain name filtered out as spam. The second purpose is for data loss prevention.

Can spammers tell if you open an email?

Some email systems include a read receipt notification option. However, the corresponding email clients of those systems also allow the recipient to block the sending of email opening confirmation while other systems, such as Gmail, only enable read receipt notifications between email addresses within its domain. A more common notification method is to include a tracking pixel in the email. When the recipient opens the email, the pixel loads from its home server, triggering a record that the email was opened. Recipients can prevent this notification process by setting a block on images loading in emails.

Can anti-spam software companies be trusted with my sensitive emails?

Anti-spam systems usually work as a filter. They don’t store emails on their own servers and so won’t compromise your privacy. Secure sensitive emails with end-to-end encryption to be sure that no proxy service can read the contents.

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