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Anti-spam
Greylisting

Anti-spam Software with Greylisting (2026)

Last updated: March 2026

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Features

Microsoft Outlook Integration(8)

Activity Tracking(7)

AI/Machine Learning(8)

Alerts/Notifications(4)

Allow/Block List(13)

Integrated with

Microsoft 365(3)

Pricing model

Free(2)

Open Source(0)

Free Trial(9)

One Time License(0)

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Mac(4)

iPad(1)

Android(2)

Linux(4)

Web-based(15)

iPhone(1)

Windows(6)

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Small Business(14)

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Large Enterprises(14)

Public Administrations(7)

Freelancers(8)

Mid Size Business(13)

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Heimdal Email Security

5.0

(1)

Based on GetApp‘s extensive, proprietary database of in-depth, verified user reviews

Email Protection in a Redefined Spam Filter

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Heimdal Email Security is an email protection solution that combines advanced spam filtering with robust malware prevention through a multitude of modern technologies.

ContentCatcher

4.9

(12)

Based on GetApp‘s extensive, proprietary database of in-depth, verified user reviews

Cloud-based email security, phishing protection & anti-spam

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ContentCatcher is a web-based SaaS solution offering email security, encryption, anti-spam, phishing protection and compliant archiving to assist organizations of all levels to combat and mitigate malicious email threats, with features including anti-virus, filtering, URL defense, reporting and more

SpamTitan

4.6

(563)

369

156

Based on GetApp‘s extensive, proprietary database of in-depth, verified user reviews

Anti-spam filter for business email. Vital email security.

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SpamTitan blocks spam, viruses, malware, ransomware, phishing attempts and other email threats. SpamTitan provides advanced yet easy to use email security for your business. Office 365 friendly

Graphus

4.3

(27)

Based on GetApp‘s extensive, proprietary database of in-depth, verified user reviews

Cloud-based email security software

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Graphus is a cloud-based anti-phishing software, which helps protect organizations against email attacks, credential theft, malware, ransomware, identity spoofing, brand impersonation, business email compromise (BEC), account takeover (ATO) and other threats.

SpamHero

4.5

(15)

Based on GetApp‘s extensive, proprietary database of in-depth, verified user reviews

Saving the world from spam, one domain at a time!

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SpamHero is a cloud-hosted spam filtering solution available. Stop the spam, viruses, and phishing attacks before they reach your network.

Mailinblack

4.5

(13)

Based on GetApp‘s extensive, proprietary database of in-depth, verified user reviews

Cloud-based & on-premise email protection software

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Protecting businesses from malware, phishing, ransomware, and spam emails.

spambarrier

(0)

First-class spam and virus protection for your domain.

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Spambarrier is a service that filters your emails before they reach your mail server. The easy way to protect yourself from spam Hosting securely in Germany and compliant with data protection regulations.

EuropeanMX

(0)

Cloud-based anti-spam for incoming and outgoing messages

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Use the cloud redundancy solution EuropeanMX as a reliable spam filter. Our system offers nearly 100% filter accuracy and virtually no false positives. Protect your IP ranges before getting blacklisted. Continuously archive your emails with EuropeanMX to always have a backup of your emails.

Security Gateway by MDaemon

4.9

(15)

Based on GetApp‘s extensive, proprietary database of in-depth, verified user reviews

Powerful yet flexible email security software.

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Security Gateway by MDaemon is an email security software designed to help businesses secure email servers from malware and phishing attacks. The solution enables administrators to automatically detect threats across various platforms including Microsoft Exchange Server and Office 365.

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Users also considered

ESET PROTECT MDR

4.8

(16)

Based on GetApp‘s extensive, proprietary database of in-depth, verified user reviews

Future ready protection for enterprise

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Airtight protection of your IT environment,
with complete cyber risk management and
world-class ESET expertise on call.

Microsoft Defender for Office 365

4.6

(235)

152

Based on GetApp‘s extensive, proprietary database of in-depth, verified user reviews

Cloud-based email security and threat management software

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Microsoft Defender for Office 365 is a cloud-based email security software designed to help businesses automatically detect, investigate, and resolve potential email threats on a centralized platform. Supervisors can configure security policies, perform spoof checks, and maintain a record of reported incidents.

Read more about Microsoft Defender for Office 365

Users also considered

SpamTitan Plus

(0)

Zero-day threat protection and intelligence

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SpamTitan Plus is an anti-phishing solution, which provides features such as URL inspection, malicious link neutralizing, URL rewriting, and time-of-click analysis.

Trustifi

4.9

(18)

Based on GetApp‘s extensive, proprietary database of in-depth, verified user reviews

Protect Your Business Emails with AI-Powered Security

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Email security solution that helps manage threat detection, regulatory compliance, data encryption, whitelisting/blacklisting, and more.

Abnormal AI

5.0

(2)

Based on GetApp‘s extensive, proprietary database of in-depth, verified user reviews

A Fundamentally Different Approach to Email Security

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Abnormal provides total protection against the widest range of attacks including phishing, malware, ransomware, social engineering, executive impersonation, supply chain compromise, internal account compromise, spam, and graymail.

ALTOSPAM

4.8

(73)

Based on GetApp‘s extensive, proprietary database of in-depth, verified user reviews

Effectively protect all your company's emails

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ALTOSPAM is an email protection solution for all businesses, associations and local authorities. Choose advanced email security compatible with all mail servers, including Office 365. Try ALTOSPAM for free.

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