Whitelist and Blacklist domain in zimbra 8.6

Introduction

In today’s digital landscape, managing email security is critical for organizations. Zimbra, a robust email collaboration suite, offers powerful features to filter email traffic using domain whitelisting and blacklisting. This functionality ensures only trusted domains can communicate, while malicious or spammy domains are blocked effectively. This guide provides a comprehensive overview of how to configure and use these features in Zimbra, along with practical examples and FAQs.

Why Use Whitelisting and Blacklisting in Zimbra?

Benefits of Email Filtering

1. Improved Security: Protects users from phishing and malware-laden emails.

2. Reduced Spam: Prevents unsolicited messages from cluttering inboxes.

3. Customizability: Tailor filters to meet organizational needs.

4. Operational Efficiency: Enhances productivity by minimizing distractions from spam.

How Whitelisting and Blacklisting Work

Whitelisting allows emails from specified domains or addresses, bypassing spam filters. Blacklisting, on the other hand, blocks emails from specific sources outright. Both features can be managed at the server or user level in Zimbra.

In this  tutorial, How to configure whitelist and blacklist domain in zimbra. To use amavisd.conf.in file before it's configure, To backup file /opt/zimbra/conf/amavisd.conf.in we need to score Positive is Blacklist and Negative score is whitelist. I'm running the commands with account zimbra ( su - zimbra)

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Configuring Whitelist and Blacklist in zimbra 8.6

To backup amavisd.conf.in file

su - zimbra
cp /opt/zimbra/conf/amavisd.conf.in /opt/zimbra/conf/amavisd.conf.in.bak

How to whitelist domain in zimbra

To add whitelist domain or emailID  in amavisd.conf.in file

vim /opt/zimbra/conf/amavisd.conf.in

The content whitelist domain as below:

{ # a hash-type lookup table (associative array)
'example.com' => -10.0,
'nobody@cert.org' => -3.0,
'huuphan.com' => -20.0,
'devopsskills.info' => -20.0,

To restart zimbra amavisd service

zmamavisdctl restart

How to blacklist domain in zimbra

To add blacklist domain  or emailID in file amavisd.conf.in

vim /opt/zimbra/conf/amavisd.conf.in

The content blacklist domain as below:

{ # a hash-type lookup table (associative array)
'emailid@example.com' => 10.0,
'@mail.example.com' => 10.0,

To restart zimbra amavisd service

zmamavisdctl restart

To check zimbra.log log

tailf /var/log/zimbra.log

FAQ Section

Can I whitelist or blacklist specific email addresses instead of entire domains?

Yes, both email addresses (e.g., user@domain.com) and domains (e.g., domain.com) can be added to the respective lists.

How do I prioritize whitelisted domains over blacklisted ones?

Zimbra processes whitelisted domains before blacklisted ones, ensuring allowed domains are not accidentally blocked.

Are there limits to the number of entries in whitelist/blacklist?

While there is no strict limit, excessive entries can impact performance. Regularly review and optimize lists.

How do I view current whitelist and blacklist entries?

Use the following command:

zmprov gacf | grep amavis

External Resources

1. Official Zimbra Documentation

2. Understanding Anti-Spam in Zimbra

3. Amavis Configuration Guide

Conclusion

Mastering domain whitelisting and blacklisting in Zimbra empowers administrators to secure email communication and minimize spam. With the steps outlined above, you can customize filters to protect your organization effectively. Regular monitoring and optimization of these lists ensure sustained performance and security.

Enhance your Zimbra experience by exploring additional features and integrating third-party tools for a comprehensive email management solution.