Tips for improving your Zimbra experience.
In this post, we’ll show you how doing selective Postfix rate limiting will improve your Zimbra system’s email deliverability. Various trade press accounts have reported that COVID resulted in email volumes essentially doubling. For large email providers, especially the free email providers like Gmail, Yahoo and Outlook.com, they have had …
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 attempts typically come from 10 to 20 or so different IP addresses from around the globe, and are infrequent enough that Zimbra’s Denial of Service …
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, redundancy and resiliency — and with very short RPO (Recovery Point Objective) and RTO (Recovery Time Objectives) targets. For single-server installations, you can still use …
May 2023 Update: If you have come to this page via a link, please note this page has been deprecated in favor of our new Fail2Ban Best Practices blog post, which you can get to by clicking here. In a previous blog post, I documented how to configure Zimbra’s …
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 domain won’t be spoofed by bad actors, often because they presume that email that spoofs their domain would be blocked by the recipients. But that’s …
Do any of these describe your Zimbra system? You have a large mail store (1TB or more) Your Zimbra system is busy with a lot of inbound and/or outbound emails every day You keep backups for a long time You believe you have plenty of RAM but you are finding …
Back in 2014 I wrote a good chunk of the Zimbra Anti-Spam Strategies community wiki. In the intervening eight years, a lot has changed, but unfortunately email remains the number one attack vector for malware, phishing, whaling and other scams. In this blog post, continuously updated since March 2019, we …
During the past several years I have migrated a number of Zimbra systems to Amazon Web Services (“AWS”). These “real-world” experiences led to my being invited by Zimbra to present my AWS Hosting Best Practices at their North American Partners’ Conference in Dallas, Texas in October 2018. Since that time, …
We use a variety of monitoring tools to make sure we know what’s what with our Zimbra Hosting environment, and we are pleased to announce that customers now have access to our “outside-in” monitoring (courtesy of UptimeRobot). You can see the uptime report for all of our Zimbra’s public-facing services …
Email is one of the top attack vectors for getting inside an organization, and it is a known fact that we are more likely to open an email that purports to come from someone we know. The spammers of course know this too, and recently, they have been exploiting it …
