Zimbra saves a mailbox as a .tgz export, and Outlook cannot open that file. To move Zimbra to Outlook you convert the .tgz to PST, the format Outlook reads. The Univik Zimbra Converter handles it in a few clicks and saves your folders, attachments, calendar and dates. A free manual route works too, though it drops most of that on the way.
You are leaving Zimbra and your mail is sitting in a .tgz export that Outlook will not touch. The messages, the folders you sorted over the years, the calendar and the contacts are all zipped inside one archive. To read them in Outlook you need a PST. This guide covers the quick way to convert Zimbra to PST, the free manual way and what each one keeps, so you can migrate Zimbra to Outlook without losing a thing.
What a Zimbra TGZ Export Is
When you export a mailbox from Zimbra, the server wraps it into a single .tgz file, which is really a gzip-compressed tar archive, the same file type as a tar.gz. Inside sit your messages as plain .eml files, laid out in the same folders you had, next to a small meta.xml. That meta.xml is the metadata map: it records the folder path, the tags, the flags and whether each mail was read. Contacts and calendar entries ride inside the same archive. That neat archive is easy for Zimbra to hand over, but Outlook cannot read it, which is why a Zimbra to Outlook move needs a conversion step first. If the server crashed before you could make this export, that is a different job. Our guide on crashed Zimbra Server mailbox recovery covers pulling mail out of a broken store.
The Fastest Way to Convert Zimbra to PST
The short path is a converter built for the format. It reads the .tgz without Outlook or a Zimbra server, rebuilds each folder in bulk and produces an Outlook PST. The whole convert runs offline on your Windows PC and nothing is uploaded, so you launch Outlook and the mail is already there. You can try it on the free trial first. The Univik Zimbra Converter runs the whole job in four steps, the entire Zimbra to Outlook move in one place.
- Add your .tgz exportPoint the tool at the file you downloaded from Zimbra Preferences or the zmmailbox command.
- Choose PST as the outputPick Outlook PST when you want the result to load in Outlook, or EML, EMLX, MSG, MBOX, PDF, HTML and CSV. You can also send it on to Thunderbird, Gmail or Office 365.
- Keep folders and datesLeave the folder, attachment and date options on so the mailbox comes over whole.
- Convert and openRun it, then load the PST in Outlook and every folder is in its place.
The Univik Zimbra Converter reads your .tgz export, restores each folder and builds a clean Outlook PST that keeps attachments, calendar and dates. No mail server has to be running.
Free Download See All FeaturesWhat the Zimbra to PST Conversion Keeps
A converter carries across much more than the plain text. The folder tree arrives in the PST exactly as you set it up. Each attachment stays fixed to the mail it came on. Address book entries and calendar items turn into their Outlook forms, and the sender line, the timestamps and the read marks follow along, so the PST feels like the mailbox you knew rather than a loose pile of messages. The finished PST opens in Classic Outlook, and the same tool can push the mail straight to an IMAP or Office 365 account instead.
The Manual Way to Move Zimbra to Outlook
There is a route that costs nothing, and it helps to know where it stops short. You unzip the .tgz to an empty folder with an archive tool such as 7-Zip, which gives you the .eml messages and the meta.xml. In Outlook you make a fresh folder, then drag those .eml files into it a few at a time so the app keeps up. This is the free way to import Zimbra to Outlook by hand. With the mail in place, open File and choose Open and Export. Run Import and Export, then save that folder as an Outlook Data File in PST form.
The problem is what gets lost. Dragging mail into Outlook can reset the sent date to the day you imported it. The folders you had in Zimbra collapse into one flat pile. Tags and read marks are gone, and the calendar and contacts need a separate step as VCF and ICS files. Outlook also has to be on the same computer, and the process gets very slow once the export is large. For a handful of mails it is fine. For a real account it is a lot of work for very little.
Moving Zimbra Contacts and Calendar to Outlook
A Zimbra account is rarely only mail. The export can also hold your address book and your calendar, and those matter as much as the inbox on moving day. A converter writes the contacts as VCF (vCard) files and the calendar entries as ICS files, or writes them into the PST, so they arrive next to your mail rather than being left in the archive. The manual route skips them unless you export and import each one on its own, which is one more reason a full Zimbra to Outlook move leans on a tool.
ANSI and Unicode PST for a Big Zimbra Mailbox
Outlook keeps mail in one of two PST types, and the choice matters because a Zimbra account is often large. The older ANSI PST stops near 2 GB and covers a limited character range. The Unicode PST, standard from Outlook 2003 onward, carries a 50 GB allowance in Outlook 2010 and newer that a registry tweak can raise. Beyond a small account, Unicode is the one to choose. Microsoft lists the size limits for PST files if you want the exact numbers. A capable converter lets you cap the size and split the result so no single PST grows too big to handle.
Why Teams Move from Zimbra to Outlook
A Zimbra to Outlook migration usually starts with a plan to leave Zimbra behind. Keeping a Zimbra Collaboration Suite (ZCS) server running costs staff time that many teams would rather spend elsewhere, and plenty of them migrate to Microsoft 365. Once the server is switched off, the old mail still has to open. A PST loads in any modern Outlook with no server running. Some people only want a personal archive they can move between computers. Either way, the export has to become a file Outlook can read. That file is a PST.
When Convert Zimbra to PST Comes Up at Work
This task tends to land on a desk for a few familiar reasons. An employee moves on and their account still has to be read. A firm shuts down its Zimbra server, so every mailbox needs somewhere else to live. An audit or a legal hold asks for old mail to be opened and searched in software the team already runs. An archived account has to stay readable for years to come. Each of these ends the same way: the .tgz export must turn into a PST, and a converter carries the folders over intact.
Tested and Verified: Zimbra to PST Results
Before this guide went out, the Univik team ran the Zimbra to PST conversion against real exports rather than a single sample. We pulled .tgz files from Zimbra Collaboration 8.8.15 through the 10.x line, and from the Zimbra Desktop client, then verified the Outlook PST against the source. In every run the message count in the PST matched the count in the export. The folder tree came across in the same shape, and attachments, contacts and calendar items all arrived. Sent and received dates stayed on each message, which is the part the free drag route tends to break.
Zimbra to PST Questions
Put together by Leena Taylor Paul with the Univik team, who have built Windows data conversion software since 2013. A single export hides an entire mailbox inside one archive, so this guide keeps its focus on carrying the mail, folders, calendar and dates over without the losses the drag route brings. Last checked September 2026. Cannot get an export to open? Reach our support team.