Mission Critical Email Is All We Do
Mission Critical Email Is All We Do

More than 100 companies rely on us for their mission-critical Zimbra Hosting, Training and Professional Services, Microsoft 365 and Mimecast Security, Compliance and Continuity.

Hardened Zimbra Hosting
Hardened Zimbra Hosting

We host more than 60 global and domestic companies in our hardened, HIPAA-compliant Zimbra environment on Amazon Web Services.  Learn why Zimbra themselves asked us to present on AWS Hosting Best Practices at the recent North American Partners conference.

Zimbra Professional Services
Zimbra Professional Services

For more than 12 years our Zimbra Professional Services have satisfied scores of Zimbra customers and other Zimbra partners globally. We solve thorny issues including: Life Cycle upgrades and migrations; Disaster Recovery; Security Hardening and Compliance.

Zimbra Certified Training
Zimbra Certified Training

We are the leading Zimbra Certified Training Partner in the United States, and we supplement Zimbra’s core curriculum with our bespoke Best Practices from more than a decade of Zimbra Hosting.

Who We Are

We are the global Zimbra experts with customers in 20 states and 10 countries. Our proprietor, Mark Stone, adopted Zimbra for his own company in 2005 and became a Zimbra Partner in 2006.  We have...
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What We Do

We provide our customers with email systems that are performant, reliable, secure and cost-effective — systems that meet each customer’s Mission Critical Email needs. Zimbra Hosting, Licensing, Training and Professional Services Mission Critical Email is...
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Recent Zimbra Blog Posts

How To Defend Zimbra Against Distributed Brute Force Login Attacks
Increasingly we are seeing distributed brute force login attacks on our Zimbra hosting environment, as well as on our on-premises customers' Zimbra systems. These login...
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Architectural Design Reference for Large Zimbra Deployments in Amazon Web Services
This post documents a high-level architectural design reference for hosting large Zimbra deployments in Amazon Web Services cost-effectively, with a high degree of security, performance,...
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Zimbra Fail2Ban for Submission Only
In a previous blog post, I documented how to configure Zimbra's DoSFilter in conjunction with a Failed Lockout Policy with the objective of blocking a...
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Zimbra Gandi SSL Certificate Installation
This post will you show you how to install Gandi SSL certificates in Zimbra with the new Sectigo certs that have replaced the expired Comodo certs.
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Office 365 Address Verification, SPF, DMARC and DKIM
To date, when most people think of anti-spam, they think of blocking inbound spam. Most people don't think about taking steps to ensure that their...
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Zimbra Patching – Recommended Best Practices 2019
During yesterday's Zeta Alliance call, Zimbra Patching, recent Zimbra exploits and their mitigation were a featured topic of discussion.  The Zimbra forums have some very...
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Java Improvements Make Upgrading Zimbra Attractive
Zimbra 8.8.12 quietly replaced Java 8 with Java 11, and combined with a change in Java Garbage Collectors, we are seeing significant mailbox server performance...
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Zimbra Anti-Spam Best Practices – Updated for 2020
Back in 2014 I wrote a good chunk of the Zimbra Anti-Spam Strategies community wiki. In the intervening six years, a lot has changed, but...
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