Univik MailStore Server Converter

Yes, completely. MailStore exports preserve the original mailbox folder hierarchy inside the ZIP — Inbox, Sent Items, Drafts, Deleted Items and all custom folders. The converter reads this sub-folder structure from the ZIP and recreates it exactly in the output format. In PST output, folders appear in Outlook exactly as they did in MailStore. In MBOX output, folder names are preserved as MBOX labels for Google Workspace import.

Yes — this is the most common MailStore migration path. Convert each user's MailStore ZIP export to PST. The resulting PST files upload directly into Microsoft 365 via the M365 Import Service (network upload or drive shipping). One PST per user maps to one M365 mailbox. The complete folder structure is preserved so archived emails appear in the correct folders in the user's M365 mailbox after import.

MailStore Server generates a CSV audit log alongside every export listing every message exported with its metadata (sender, recipient, date, subject, size). Univik MailStore Server Converter reads this log and cross-references it with the converted output to confirm that every message in the log is present in the output. Any discrepancies are flagged in the conversion report before you decommission MailStore. This completeness verification is particularly important for compliance obligations under GDPR and similar data retention frameworks.

Yes. MailStore Home (the free personal edition) produces the same EML+ZIP export format as MailStore Server. Univik MailStore Server Converter handles both editions identically. Users moving from MailStore Home to Microsoft 365 or Google Workspace can use this converter for the migration without any difference in process.

Yes. Convert MailStore ZIP exports to MBOX format. MBOX files import into Google Workspace using Google's migration tools or third-party tools such as BitTitan. One MBOX per user ZIP maps to one Google Workspace mailbox. Folder labels from the MailStore folder structure are preserved in MBOX output for Google Workspace import.

No, completely standalone. Once you have exported the ZIP or PST files from the MailStore Management Console, no MailStore server, Management Console or MailStore client is needed on the conversion machine. The converter reads the export files as standalone archives. The MailStore server can be offline or decommissioned before conversion is complete.

Minimal requirements:

• OS: Windows 11, 10, 8.1, 8 or 7
• RAM: 4 GB minimum (8 GB recommended for large multi-user exports)
• Disk: 50 MB installation plus space for output files
• Framework: .NET Framework 4.8 or higher

No MailStore client, Outlook or internet connection required.

Free trial converts the first 25 messages per archive. All features fully functional: ZIP loading, folder structure preservation, audit log reading, all 10+ output formats and preview. No time limit. Verify folder mapping and message completeness before purchasing ($29 personal, $99 business).

Steps: (1) Open the MailStore Management Console, (2) Go to Archive Email → Export, (3) Select the users to export, (4) Choose EML or PST as the output format, (5) Set the output folder path, (6) Click Run and wait for completion, (7) Collect the per-user ZIP files and audit log from the output folder, (8) Load into Univik MailStore Server Converter. For large deployments, schedule the export during off-peak hours as MailStore export is I/O intensive.