Univik Kerio Converter for Windows
Quick Facts
Key Features
Kerio Converter for the Whole Store
The server keeps each message as a plain .eml file inside a #msgs folder for every mailbox folder. The software walks the store tree, domain by domain and user by user, so nobody collects those files by hand.
Quick Facts
At a Glance The Kerio converter in five numbers: sources, targets, installs, accounts and price
3
Kerio Sources
Store folder, .fdb file or the accounts configured on the PC.
12
Output Targets
Three file groups, three mail services, one client and SQL.
0
Kerio Installs
The server and its licence are not needed on the PC.
All
Accounts per Run
Every mailbox in the store goes through in one batch.
$299
For 2 PCs
One payment, no subscription, 30-day refund promise.
Key Features
What the Kerio Converter Does Eight things the software handles that a manual export or an IMAP move does not
.fdb Files From Kerio Outlook Connector
Kerio Outlook Connector (Offline Edition) keeps a copy of each mailbox in .fdb database files under the user profile. The converter opens those files, so a mailbox survives when the server is gone.
All Configured Accounts in One Batch
Every account set up on the PC is picked up together. One run covers them all, with no per-mailbox count on the licence.
Contacts and Calendars Come Along
Kerio stores contacts and calendar items inside the same mailbox folders as the mail. The converter carries them across with the messages.
No Kerio Server on the PC
The server install and its licence are not needed. A copied store folder on any Windows 11 or 10 PC is enough.
Export Menu With 12 Targets
Email Files gives EML, MBOX and PST. Document Files gives PDF, HTML, TEXT and CSV. Email Services gives Gmail, Office 365 and IMAP. Thunderbird and a SQL script complete the list.
Direct Upload to Gmail, Office 365 or IMAP
Mail can go straight into a Microsoft 365 or Google account during the run. The IMAP target reaches any other mail server you host.
SQL Script for a Database
The Scripts group writes a SQL script of the mail, so a database can hold the archive for search and reporting.
The Problem
Why Admins Need a Kerio Converter Two lines from GFI's own knowledge base explain the search
GFI documents the store, the backup format and the restore tool in detail. It does not document a way out.
GFI Has No Way Out
GFI's knowledge base states that there is no official tool for migrating content out of Kerio Connect. Its own migration tools carry mail into Kerio, never out. Support treats the trip out as outside its scope.
IMAP Leaves Half the Mailbox Behind
An IMAP migration into Microsoft 365 copies mail folders only. Contacts, calendars and tasks stay on the Kerio server. Each mailbox also needs its own password, which the admin rarely holds.
Read the Store Instead
Univik Kerio Converter works from the store copy or the .fdb files, so no mailbox password and no running server are needed. Contacts and calendars travel with the mail. The output can be a PST for Outlook or a direct upload to the new tenant.
Three Sources
Three Kerio Sources, One Tool Where each kind of Kerio data lives and what to hand the converter
STORE
Kerio Connect store folder
GFI lists the default paths as C:\Program Files\Kerio\MailServer\store on Windows, /opt/kerio/mailserver/store on Linux and /usr/local/kerio/mailserver/store on Mac. Inside, mail\domain\user holds one folder per mail folder, each with a #msgs folder of .eml files. Copy it to a Windows PC and open it.
.FDB
Kerio Outlook Connector database
This Outlook add-in keeps a local copy of the mailbox. GFI places its files under the user's local AppData folder in Kerio\Outlook Connector\<profile name>, as one BASE.fdb plus one database per mailbox. Open that folder when only the user PC is left.
ACCOUNTS
Configured Kerio accounts
Every account set up on the Windows PC. The tool lists them and converts them in one batch, which saves a mailbox-by-mailbox export when a whole office moves.
Want to look at one message before a full run? Any .eml file from a #msgs folder opens in the free online EML viewer in a browser.
Three Steps
Three StepsHow to Convert Kerio Connect Mail Collect the source, choose a target on the Export menu and check the result
1
Collect the Kerio Source
Stop the Kerio Connect server and copy its store folder. Or locate the .fdb files under the user profile. Or use the accounts already configured on the PC.
2
Open It in Univik Kerio Converter
Start the software, pick the source type and choose the folder or file. Open the Export menu and pick one of its five groups, from Email Files to Scripts.
3
Run It and Check the Result
Press the run button. Then open the result in Outlook, Thunderbird, a PDF reader or the target mailbox and compare folder names and item counts with the source.
Download the Free Trial
The trial run saves 10 items from each folder. Compare its output with the source before you buy.
Typical Jobs
Typical JobsWho Uses the Kerio Converter Three situations where the store copy is the only thing left to work with
Server Dead or Switched Off
The Kerio box failed or was retired. Only a disk image or a backup ZIP remains. The store folder inside it still converts on any Windows PC.
Licence Expired
GFI suspends every function of Kerio Connect on expiry day and has given no grace period since May 2023. Users cannot log in. The store on disk is intact and so is each user's .fdb cache.
One Mailbox for Legal or HR
A review needs one user's mail as PDF or PST without touching the live server. Convert that user's folder from a store copy and hand over the files.
Prefer a done-for-you move with cutover planning and delta passes? That is the Kerio migration services page. This page is the self-serve tool.
Good to Know
Good to KnowThe Kerio Outlook Connector Problem Why the .fdb cache deserves a copy before the next Outlook update
New Outlook
Kerio Outlook Connector is a COM add-in, so GFI confirms it does not work in the new Outlook. The fallback is a plain IMAP account, which syncs neither calendars nor contacts.
Convert the .fdb cache or the store once and keep an open copy in PST or EML. After that, an Outlook update or a lapsed licence cannot lock the mail away.
Side by Side
Three Ways Out of Kerio Connect What each route needs from you and what it leaves behind
| What you need | Microsoft 365 IMAP Migration | Outlook Connector Export | Univik Kerio ConverterTRIAL |
|---|---|---|---|
| Works without the Kerio server | No | No | Yes |
| Contacts and calendars | Left behind | One profile at a time | Included |
| Mailbox passwords needed | Every mailbox | The user's own | None |
| All accounts in one run | Batch by CSV | No | Yes |
| Output choice | Microsoft 365 only | PST, one mailbox | 12 targets |
| Works in the new Outlook | Yes | No | Not needed |
| Price | Admin time | Free with Outlook | From $299 |
The IMAP route fits mail-only moves with a live server and every password in hand. The converter is for every other case.
What You Need
System Requirements for the Kerio Converter A Windows PC, the .NET Framework and a copy of the source data
Windows 11 or 10, 64-bit
The software runs on a desktop or laptop, not on the server. A Linux or Mac store is copied to this PC first.
.NET Framework 4.8 or newer
Windows 11 and recent Windows 10 builds already have it.
A copy of the source
The store folder, the .fdb files or the configured accounts. Stop the server before you copy its store, as GFI advises.
Disk space for the output
Allow the size of the source for PST or EML output. Outlook limits a PST file to 50 GB by default.
| Software Information | Univik Kerio Converter |
| Version | Latest release, free 1 year upgrade included |
| Licence | Personal $299 for 2 PCs, Business $499 for 10 PCs, Enterprise $999 for 50 PCs |
| Platform | Windows 11 or Windows 10, 64-bit desktop |
| Framework | .NET Framework 4.8 or newer |
| Reads | Kerio Connect store folder, Outlook Connector .fdb files, configured accounts |
| Trial | 10 items per folder |
| Refund | 30 days on every licence |
Questions
Kerio Converter FAQ Nine questions buyers ask before they run the trial
No. The software reads a copy of the Kerio Connect store folder, the .fdb files of Kerio Outlook Connector or the Kerio accounts already configured on the PC. The server, its licence and its database are not needed on the Windows PC that runs the conversion.
Three sources. First, the store folder of a Kerio Connect server, where every message sits as a plain .eml file inside a #msgs folder. Second, the .fdb database files of Kerio Outlook Connector (Offline Edition). Third, every account configured on the PC, converted together in one run.
Yes. GFI suspends every function of Kerio Connect on the day the licence expires and has given no grace period since 1 May 2023. The store folder on disk is not touched by that lock. Copy it to a Windows PC and the converter reads it with no licence check of its own.
Yes. Kerio Connect stores contacts and calendar items inside the mailbox folders. The converter carries them across with the messages, which an IMAP migration cannot do.
The price covers a server, not a mailbox. One licence converts every account in the store with no per-mailbox count. It writes to 12 targets including a SQL script and installs on 2 PCs. A free 1 year upgrade and a 30-day refund promise are included. Business covers 10 PCs at $499 and Enterprise covers 50 PCs at $999.
Yes. The Email Services group on the Export menu lists Gmail, Office 365 and IMAP. Mail goes into the chosen account during the run. The IMAP target also reaches any other mail server you host.
The server writes backups as ZIP files named F, D or C plus a date stamp, with the store inside an @backup folder. Extract the store folder from that ZIP first, then open it in the converter.
No. Everything runs on your own Windows PC and the output lands in a folder you pick. Mail leaves the PC only if the target you pick is Gmail, Office 365 or IMAP. Then it goes to the account you entered.
Yes. The trial runs the full process and keeps 10 items in every folder, enough to check folder names, dates and attachments on your own store. A licence removes the limit.
More Tools
Beyond Kerio: More Server Converters The same offline approach for Zimbra, Synology, TerraMaster and other servers
Page reviewed by Nick Rogers Univik founder, since 2013
Fact Checked
Facts about the Kerio Connect store, the .fdb files of Kerio Outlook Connector, backup names and GFI's migration guidance were checked against GFI's knowledge base and manuals in October 2026. Every product claim describes Univik Kerio Converter as its maker specified it.
Prices, the 2, 10 and 50 PC licence tiers, the 30-day refund promise and the free 1 year upgrade match the buy page.
Last reviewed on 22 October 2026
Since 2013Sources VerifiedNick Rogers