With a new webmail interface
It looks like Synacor, Zimbra's owner at this point, is doing a great job — unlike some companies that bought the software and did practically nothing. Synacor is driving a subtle and promising evolution of the product.
To make things more interesting for developers, there is now a new way to compile a development version, zm-build, available on Zimbra's GitHub. I hope this same build will soon be possible for Debian and openSUSE.
The latest Zimbra version I tested was 8.7.1, which has an installation video on the channel, and it was already much lighter than its predecessors. The trend is for it to become lighter still.
But for a simpler environment, without much hardware to spend on email, I still suggest ISPConfig with Postfix. I know I am biased, but let's face it: you cannot be lightweight while using Java, two HTTP servers, and a ton of processes in .jar. If you doubt it, try bringing up Zimbra on a server with 2 GB of RAM and see what happens.
Zimbra Universal UI — public beta
During the first COMMIT, Zimbra's technology and development event, the new Universal UIwas presented: a redesigned interface for Zimbra Collaboration, with modern standards and a focus on improving the user experience.
New calendar view
The calendar was redesigned with a modern look. One highlight is the new way to add events quickly, without popups, for greater efficiency.
New contacts view
For contacts, a more modern avatar display. If a contact does not yet have an image, Zimbra shows their initials.
New tasks view
The tasks view became cleaner, replacing the progress bar with a progress circle.
In 2017, this section invited users to test Universal UI on a cloud instance and linked to the developer build. Both addresses went offline — and the next section explains why.
What happened to Universal UI
It never left beta. The original announcement post on Zimbra's blog, dated 27 March 2017, now opens with a notice added later: “While we are suspending plans for Universal UI’s release, we are aggressively advancing another exciting project…” — we are suspending plans to release Universal UI. The cloud beta was shut down, the developer build went offline, and the subject died.
The idea survived, though. What Zimbra described as “another exciting project” became the Modern Web App, launched with Zimbra 9 (GA on 7 April 2020). It is the same thesis — the 2005 Ajax interface retired, the interface rewritten with modern tooling — only delivered three years later under another name. In the 10.1 series, the product continues to offer both: the Modern Web App and the Classic Web App, the old client many people refuse to let go of.
It serves as a reminder when reading technical news: a public beta presented at an event is not a roadmap. Between a demo and a release, there is room for a full cancellation.
If you still run Zimbra 8, read this
The 8 series is over. 8.8.15 Joule, which was the most widely installed LTS in Brazil, had guidance through 31/12/2024; 9 Kepler had extended support through 30/06/2025. An 8.7.7 like the one in this news story has gone unpatched for many years — and unpatched webmail is not a legacy system, it is an open door.
The scale of the risk is not theoretical. CVE-2025-27915, a stored XSS in the Classic Web Client exploited through an attachment .ics, was used in a campaign targeting the Brazilian Armed Forces — simply opening the message let JavaScript run in the victim's session and create a filter forwarding the entire mailbox. The fix shipped on 27 January 2025, for 9.0.0 Patch 44, 10.0.13, and 10.1.5. Anyone on an unsupported series received no fix at all.
Today's path:
# o que você tem rodando
su - zimbra -c 'zmcontrol -v'
su - zimbra -c 'zmcontrol status'
- Series 10.1 is current, with General Support through 31/12/2027. Upgrading from 8.8.15 or 9 involves the migration tool for Zextras' NG modules, which were absorbed into the core in series 10.
- Supported systems in 10.1: Ubuntu 22.04/24.04 and RHEL/Rocky 8 and 9. Ubuntu 16.04 from the time of this post is not included.
- The official binary's rules changed. Since 10.1, downloading requires a key, even for trials. The Open Source Edition still exists, but you build it from zm-build — it is no longer the free tarball you could download in 2017.
And the resource argument from above still stands: if you need lean IMAP and webmail, rather than full groupware with shared calendars and an Outlook connector, ISPConfig with Postfix does the job with a fraction of the hardware. Zimbra wins when the requirement is the entire collaboration package.
To keep going
- The history of the Zimbra server — from LiquidSys to Daffodil, through Yahoo, VMware, Telligent, and Synacor
- Installing Zimbra 8.7.1 on Ubuntu — the period how-to, preserved as a record
- Hosting with ISPConfig — the lightweight alternative
- Zimbra Collaboration 8.7.7 now available — the original announcement
- Zimbra — product lifecycle — support dates for each series