A 5-minute walkthrough of converting MDaemon mail server data to standard formats (PST, MBOX, EML, PDF) or migrating directly to cloud accounts (Office 365, Gmail, Exchange) using the 4n6 MDaemon Converter. Useful when retiring an MDaemon server, migrating staff to cloud email, or producing forensic-grade PDF archives for legal preservation.
Video Transcript
Hello and welcome. This video shows how to convert MDaemon mail server emails into standard email formats like PST for Outlook, MBOX for Thunderbird, EML, PDF or how to migrate them to cloud accounts like Office 365 and Gmail. We use the 4n6 MDaemon Converter tool which handles MDaemon's native MSG and MRK file formats without needing MDaemon installed.
The default MDaemon mailbox storage path is C:\MDaemon\Users\domain-name\username. Each user folder contains MSG files for emails plus MRK files for the address book, calendar, tasks and notes.
Step one. Download the 4n6 MDaemon Converter from forensiksoft.com. Install it on a Windows machine. The tool runs on Windows 7, 8, 10, 11 and Windows Server 2012, 2016, 2019.
Step two. Launch the tool. The interface auto-detects MDaemon if installed locally. If MDaemon is on a different machine, click Choose Files or Choose Folders and browse to the user mailbox path.
Step three. The tool loads the folder structure on the left panel. You see Inbox, Sent, Drafts and any custom folders, plus AddrBook.mrk, Calendar.mrk, Notes.mrk and TaskList.mrk. Tick the items you want to convert.
Step four. Pick the output format from the Save As dropdown. PST for Outlook is the most common, MBOX for Thunderbird, EML for individual messages, PDF for archiving and legal preservation, or pick a cloud destination like Office 365, Gmail or IMAP server.
Step five. Set the destination path. The tool defaults to Desktop but you can change it to any local drive or external USB. For PST output you can also tick Create Single PST or Create Separate PST per User.
Step six. Click Convert. The tool processes each folder, preserves attachments, headers, formatting, and folder hierarchy. A progress bar shows live count. When complete, a Notepad log opens with start time, end time, items converted and destination path. Thanks for watching.
What MDaemon Is and Why Conversion Is Needed
MDaemon is a Windows-based email server developed by MDaemon Technologies (formerly Alt-N Technologies, founded 1996). It is widely deployed across small and mid-size businesses that prefer on-premises email over cloud services like Microsoft 365 or Google Workspace. MDaemon handles SMTP, POP3, IMAP, ActiveSync and a custom WorldClient webmail interface, all running on the company's own Windows Server hardware.
Several scenarios push MDaemon administrators to convert mailbox data out of MDaemon's native format. The most common: migrating to cloud email when the on-premises server is being decommissioned, archiving mailboxes of departed employees in a portable format, exporting specific user mailboxes for forensic or legal review, or merging MDaemon data with an Outlook PST archive maintained separately. In all of these cases, MDaemon's native MSG + MRK file structure has to be translated into something that Outlook, Thunderbird, Office 365, Gmail or a PDF archive system can read. That is what this video covers.
The tool used in this video is the 4n6 MDaemon Server Converter, a Windows desktop application that reads MDaemon's MSG and MRK files directly without requiring MDaemon itself to be installed. This matters because most migration projects involve copying user folders from a server to a separate workstation where the conversion runs.
Tool Requirements
| Requirement | Value |
|---|---|
| Tool name | 4n6 MDaemon Converter |
| Vendor | 4n6 Software |
| Trial limit | 10 emails per folder, free download |
| Personal license | $99 for 2 PCs |
| Business license | $299 for 10 PCs |
| Enterprise license | $499 for 50 PCs |
| Operating system | Windows 7 / 8 / 10 / 11 (32 or 64-bit), Windows Server 2008 / 2012 / 2016 / 2019 |
| RAM recommended | 4 GB minimum, 8 GB for large mailboxes (10 GB+) |
| Disk space | 200 MB for the tool, plus output destination space (PST output requires roughly the same size as source MSG total) |
| MDaemon installation | Not required. Tool reads raw MSG and MRK files directly |
| Outlook installation | Not required for PST output. The tool generates PST files standalone |
| Internet connection | Required only for cloud destinations (Office 365, Gmail, Yahoo, IMAP) |
Understanding MDaemon's Native File Layout
Before converting, it helps to understand what MDaemon actually stores on disk. The default storage layout is:
| Path or file | What it contains |
|---|---|
| C:\MDaemon\Users\<domain>\<username>\ | The root folder for one user's mailbox. Contains all subfolders and metadata files for that user. |
| .\Inbox\, .\Sent\, .\Drafts\, custom folders | Each folder holds individual .msg files, one per email message. Folder structure mirrors what the user sees in WorldClient or their IMAP client. |
| AddrBook.mrk | Personal address book / contacts. The tool exports this to vCard (.vcf) or CSV. |
| Calendar.mrk | Personal calendar including events and recurring appointments. Exports to ICS. |
| Notes.mrk | Personal notes. Converts to text or PDF. |
| TaskList.mrk | Personal tasks and to-dos. Maps to Outlook tasks in PST or stays as MRK for archival. |
| HIWATER.mrk | High-water mark file used by MDaemon for delivery tracking. Generally not converted, the tool ignores it. |
| Documents.mrk | If WorldClient document storage is enabled, this holds shared documents. Exports to filesystem. |
| .IMAP folders | Hidden folders MDaemon uses for IMAP state tracking. Generally invisible in the conversion output, processed transparently. |
6 Steps to Convert MDaemon Emails
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Download and install 4n6 MDaemon Converter. Visit the 4n6 Software website and download the MDaemon Converter installer. Run the installer on a Windows machine. The tool is a single-file installation, takes about 2 minutes. The trial version converts 10 emails per folder so you can verify the workflow before buying a license.
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Launch the tool and load the MDaemon mailbox. Click Choose Files for individual MSG files or Choose Folders for a complete user mailbox. If MDaemon is installed on the same machine the tool auto-detects the storage path. Otherwise browse to C:\MDaemon\Users\<domain>\<username>. To migrate multiple users at once, point Choose Folders at the parent Users directory.
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Preview and select folders for conversion. The tool shows the folder tree on the left panel: Inbox, Sent, Drafts, custom folders, plus AddrBook.mrk, Calendar.mrk, Notes.mrk, TaskList.mrk. Tick the checkboxes next to folders you want to convert. Use the preview pane on the right to inspect individual messages with content view, hex view, raw view or message-header view (forensic-grade preview features useful for legal review).
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Pick the output format. From the Save As dropdown, pick the destination format. PST for Outlook 2007-2024, MBOX for Thunderbird and Apple Mail, EML for individual messages, PDF for legal archiving. Or pick a cloud target: Office 365, Gmail, Yahoo Mail, Outlook.com, Exchange Server, or generic IMAP server. For cloud destinations, you will be prompted to enter credentials and (for Gmail / Office 365) an app password if 2FA is enabled.
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Configure destination and options. Set the output folder. The tool defaults to Desktop, but for large migrations point it to a dedicated drive (an external USB or a network share). For PST output you can pick Create Single PST (everything merged into one file) or Create Separate PST per User (one PST per mailbox, the typical pattern for org-wide migrations). Optional filters: date range, subject contains, from/to/cc/bcc filter, skip greyed-out folders, include email header, create empty folders.
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Click Convert and wait for completion. The tool processes each folder, preserves attachments, headers, formatting and folder hierarchy. A live progress bar shows item count. When complete, a Notepad log opens with start time, end time, items converted, destination path and any skipped items. Open the destination folder to verify the output PST or MBOX file is intact.
Output Format Comparison
| Output format | Best for |
|---|---|
| PST | Migrating users from MDaemon to Microsoft Outlook (any version 2007-2024). Direct double-click import into Outlook. Most common output for Windows-shop migrations. |
| MBOX | Migrating to Mozilla Thunderbird or Apple Mail. Drag-and-drop into Thunderbird's Local Folders. Also a common source format for Linux mail tools. |
| EML | Individual message export. Each email becomes one .eml file. Imports into Windows Mail, eM Client, Mailbird, Zoho Mail. Useful when you need messages individually for legal discovery rather than as a single archive. |
| MSG | Microsoft Outlook's individual-message format. One .msg file per email. Useful for inserting specific emails as Outlook attachments or for selective archival. |
| Legal archiving and court-admissible preservation. PDF preserves visual layout and is universally readable. Each email becomes one PDF, with attachments embedded or linked. Forensic investigators prefer this format. | |
| HTML / MHT | Web archive format. Useful for publishing email archives on internal websites or for sharing with users who do not have email clients installed. |
| CSV / TXT | Bulk text export for spreadsheet analysis or data mining. Loses formatting but useful for compliance audits and bulk text searching. |
| vCard / ICS | Contact and calendar export. AddrBook.mrk converts to .vcf, Calendar.mrk converts to .ics. Imports cleanly into Outlook, Google Contacts, Apple Contacts. |
| Office 365 / Microsoft 365 | Direct cloud upload to Exchange Online mailbox. Recommended path for full SMB migrations to Microsoft cloud. Requires an app password or OAuth. |
| Gmail / Google Workspace | Direct cloud upload via IMAP. Good when migrating SMB to Google ecosystem. Requires a Gmail app password. |
| Exchange Server (on-premises) | Direct mailbox-to-mailbox migration. Useful for moving from MDaemon to a self-hosted Exchange deployment. |
| Generic IMAP server | Universal upload to any IMAP-capable server. Catch-all for migrations to providers without dedicated support. |
Common Errors and Fixes
| Error or symptom | Cause and fix |
|---|---|
| "Folder not recognised as MDaemon" | You pointed the tool at the wrong folder. The correct path is the user mailbox folder (containing Inbox, Sent, Drafts subfolders), not the parent MDaemon installation folder. Browse to C:\MDaemon\Users\<domain>\<username>\. |
| Tool auto-detects only one user despite multiple mailboxes | Auto-detect only finds the locally configured MDaemon profile. For batch migration of many users, click Choose Folders and explicitly pick the parent Users directory containing all user folders. |
| "Cannot create PST. Outlook installation problem" | The tool generates PST files standalone and does not need Outlook. If this error appears on a 64-bit Windows where 32-bit Outlook is also installed, try the 32-bit installer of the converter instead. Or output to MBOX first and convert MBOX to PST in a separate step. |
| Cloud upload (Office 365 or Gmail) fails with auth error | You used your regular account password instead of an app password. For Gmail and Office 365 with 2FA enabled, generate an app password and paste that into the tool's Cloud Upload credentials field. See our Gmail app password guide and Outlook app password guide. |
| Conversion completes but PST is corrupted | Insufficient disk space at destination, or path contains special characters MDaemon used in folder names. Pick a destination on a drive with at least 2x the source mailbox size, and use a simple destination path like D:\Migration\ without spaces or accented characters. |
| "Access denied" reading MDaemon Users folder | You do not have read permission on the MDaemon storage. Run the tool as Administrator, or copy the user folder to a location you own (e.g. desktop) before running the tool. |
| Some folders show as empty in output | The folder contained only IMAP state files (.IMAP-internal) and no actual MSG files. The tool correctly skips these. If the folder genuinely had emails in MDaemon, check the source folder on the MDaemon server to confirm MSG files are present. |
| Tool runs slowly on large mailboxes | Mailboxes over 5 GB benefit from running on SSD destination drives and 8+ GB RAM. If converting to PST, picking Create Separate PST per User produces many smaller PSTs that finish faster than one giant single PST. |
| Calendar.mrk events lose recurring rules | MDaemon's recurrence format does not always map cleanly to Outlook RRULE. The tool preserves what it can but a small percentage of complex recurring meetings may need manual fixup post-import. Test with a sample mailbox first. |
| Trial limit hit at 10 emails per folder | The free version is a 10-emails-per-folder demo. For real conversions buy a license. Personal license $99 covers 2 PCs and is sufficient for one-off SMB migrations. |
Tool Comparison: 4n6 vs Other MDaemon Converters
Several vendors make MDaemon converter tools. The major options are similar in scope (input MDaemon, output PST and other formats) but differ in price, supported destinations and specific features. The video uses 4n6 because of the forensic-grade preview features (hex view, raw view, message header view) which make it useful for legal-review scenarios as well as straight migrations.
| Tool | Notes |
|---|---|
| 4n6 MDaemon Server Converter (this video) | $99 personal / $299 business / $499 enterprise. 30+ output formats. Forensic preview (hex, raw, header view). Trial: 10 emails per folder. Windows only. |
| RecoveryTools MDaemon Migrator | Similar pricing ($99-$299). Strong cloud migration support (Office 365, Gmail, Workspace, IceWarp). Trial: 25 emails per folder. Windows only. |
| BitRecover MDaemon Converter | $89 starter, includes 25+ saving formats. 30-day money-back guarantee. Trial: 25 emails per folder. Strong format coverage. |
| CubexSoft MDaemon Converter | Multiple license editions. Direct PST + cloud migration. Trial available. Useful for organisations migrating large numbers of mailboxes simultaneously. |
| Mailsware MDaemon Converter | Lower-priced starter plans. Wide format coverage. Lighter forensic features than 4n6. |
| SysTools (no dedicated MDaemon product) | SysTools does not ship a dedicated MDaemon converter. Their MDaemon coverage works via the SysTools IMAP Migration tool (used when MDaemon is still running and IMAP is enabled), plus practical guidance in SysTools blog: Migrate MDaemon to Office 365 and SysTools updates: Migrate MDaemon to Exchange. Picked when the source server is live; not suitable when MDaemon is already decommissioned and only Users folder backups remain. |
Real Migration Scenarios
Three migration scenarios cover most real-world MDaemon conversion projects we have seen.
| Scenario | Approach and notes |
|---|---|
| SMB retiring on-premises MDaemon, moving to Microsoft 365 | The most common case. ~20-100 user mailboxes, total data 50-500 GB. Output: Office 365 cloud upload. Recommended approach: copy MDaemon Users folder to a workstation, run 4n6 converter with Create Separate PST per User to a local drive first, then upload PSTs to Office 365 via Microsoft's Network Upload tool or AzCopy. 4n6 also offers a dedicated 4n6 MDaemon to Microsoft 365 Migration product if you prefer a direct cloud-to-cloud path. The PST-intermediate approach is faster and more reliable than direct cloud upload from the converter, especially over slow Indian residential broadband. Plan one weekend of conversion work plus a working week for upload. |
| SMB retiring MDaemon, moving to Google Workspace | Similar size. Output: PST or MBOX intermediate, then upload to Google Workspace via Google's Data Migration Service (DMS) using IMAP source. Or use the dedicated 4n6 MDaemon to Gmail Migration product for direct Gmail-mailbox-to-Workspace cloud transfer. Easier path for large mailboxes: convert MDaemon to MBOX first (via the 4n6 converter), then use Workspace DMS or the 4n6 cloud migration tool to move MBOX into Gmail. |
| Legal e-discovery / forensic preservation | One or two specific mailboxes need to be preserved for litigation. Output: PDF or EML+MSG combined. The 4n6 forensic preview features (hex view, raw view, header view) are most useful here, and the 4n6 Email Forensics tool is a companion product for deeper analysis of converted output. Each preserved email becomes a court-admissible PDF with full headers and attachments. Keep the original MDaemon Users folder copy as evidence under chain-of-custody. |
| Departed-employee archive | Single mailbox, 5-50 GB. Output: PST stored on encrypted external drive or organisational backup share. Common pattern: when an employee leaves, IT freezes their MDaemon mailbox, runs conversion to PST, archives the PST per HR retention policy, then deletes the live MDaemon account. |
| Server consolidation, MDaemon to Exchange on-premises | Less common but happens when SMBs consolidate to Exchange Server while staying on-premises. Output: direct IMAP to Exchange via tools like SysTools IMAP Migration, or PST intermediate with bulk PST import via Exchange Mailbox Import Request PowerShell. SysTools also publishes a detailed guide on migrating MDaemon to Exchange Server covering the manual EAC migration-batch approach. |
Pre-Migration Checklist
Migrations go wrong when the source data is inspected too late. Before clicking Convert, work through this checklist:
| Check | Why it matters |
|---|---|
| Total mailbox size on disk | Determines destination drive requirement (typically 1-1.5x source). For 100 GB source, allocate 150 GB free space at destination. |
| Largest individual mailbox | If any single mailbox exceeds 20 GB, run that one separately. Very large mailboxes are more reliable as their own conversion job. |
| Special characters in folder names | MDaemon allows folder names with characters Outlook does not (slashes, certain Unicode). Audit the folder list in the preview before converting. |
| Active MDaemon server status | If MDaemon is still serving live mail, copy the Users folder during a maintenance window so files are not in flux mid-copy. Better still: stop MDaemon services briefly during the copy. |
| Antivirus exclusion | Add the destination folder to your antivirus exclusion list during conversion. Real-time scanning of every newly written PST file slows conversion significantly. |
| Backup of source MDaemon Users folder | Always copy the MDaemon Users folder to a separate location before running the converter, so you preserve the original in case anything goes wrong. |
| Trial run with one user first | Convert one small mailbox end to end before kicking off the full batch. This reveals issues like missing app passwords or permissions errors before you invest hours. |
| Test the output | Open the resulting PST in Outlook (or MBOX in Thunderbird) and check that messages render correctly, attachments are accessible and folder structure is preserved. Compare counts with the source. |
đź’ˇ Pro tips for MDaemon migrations
- Always work from a copy of the MDaemon Users folder, never directly against the live server. If anything goes wrong, you have the original to retry from.
- Run conversions on the destination workstation not on the MDaemon server. The server should keep serving live mail. Conversion is CPU and disk intensive.
- Pick "Create Separate PST per User" for org-wide migrations. One PST per mailbox is much easier to import into Office 365 or Outlook one user at a time.
- For Office 365 cloud destinations, use Microsoft's Network Upload tool for the final PST-to-cloud step rather than the converter's direct upload. It is more reliable on slow internet connections common in Indian SMB offices.
- Time the migration over a weekend. 100 GB of mailbox data takes hours to days depending on hardware. Plan for downtime so users do not lose new mail mid-migration.
- Preserve the MDaemon Users folder for at least 90 days after conversion. If a user reports missing email later, you can re-extract from the original.
- Test with a sample user first. Pick one volunteer with a small mailbox (sub-1 GB), convert their data, import to the destination, have them verify everything looks right. Only then proceed with bulk.
- Document the destination folder structure before conversion. Some MDaemon users have complex custom folders and you want to verify those landed in the right place in Outlook or Office 365 after conversion.
- For forensic/legal preservation, always pick PDF as the output format and keep the original MDaemon Users folder under chain-of-custody. The 4n6 hex view and raw view features are useful for verifying nothing was modified during conversion.
- If you also need to convert other email formats, see our guides for backing up Gmail/Yahoo/Outlook, converting Thunderbird to Outlook, or converting AOL PFC files.
Frequently Asked Questions
What file formats does MDaemon use natively?
MDaemon stores each email as an individual .msg file inside the user's mailbox folder, similar to maildir but with MDaemon-specific metadata. Address book, calendar, notes and tasks are stored in .mrk files (AddrBook.mrk, Calendar.mrk, Notes.mrk, TaskList.mrk). The default storage path is C:\MDaemon\Users\<domain>\<username>\ on the server. These formats are not directly readable by Outlook, Thunderbird or other clients without conversion.
Do I need MDaemon installed to use the converter?
No. The 4n6 MDaemon Converter is a standalone Windows application. It reads MDaemon's MSG and MRK files directly without needing the MDaemon server software. This matters because most migration projects involve copying user folders from a decommissioned MDaemon server to a separate workstation where the conversion is run. You only need read access to the MDaemon Users folder.
What output formats are supported?
Email formats: PST (Outlook), MBOX (Thunderbird, Apple Mail), EML (Windows Mail, eM Client, Mailbird), MSG (individual Outlook messages), EMLX (Apple Mail). Document formats: PDF, HTML, MHT, RTF, DOC, DOCX, TXT, XPS, CSV, vCard, ICS. Cloud targets: Office 365, Gmail, Google Workspace, Yahoo Mail, Outlook.com, Exchange Server, generic IMAP server. The 4n6 tool supports 30+ destination formats in total.
Can I migrate multiple MDaemon mailboxes at once?
Yes. Click Choose Folders and select the parent Users directory (e.g. C:\MDaemon\Users\example.com). The tool loads every user mailbox under that path and processes them in batch. Folder hierarchy is preserved per user. For PST output you can pick Create Separate PST per User to get one PST file per mailbox, which is the typical pattern for organisation-wide migrations to Outlook or Office 365.
Does the tool preserve attachments and metadata?
Yes. Attachments stay embedded in the converted message. Metadata preserved includes To, From, CC, BCC, Subject, Date, Time, headers, signatures, formatting (HTML and plain text), inline images and hyperlinks. The folder hierarchy from MDaemon is mirrored exactly in the output (Inbox stays Inbox, Sent stays Sent, custom folders keep their names). Forensic preview features (hex view, raw view, message header view) let you inspect individual emails before converting.
How long does an MDaemon migration typically take?
For a typical SMB user mailbox of 5,000-15,000 emails, conversion to PST takes 5-15 minutes on a normal Windows laptop. Cloud uploads (Office 365, Gmail) take longer because of internet upload speed, often 30 minutes to several hours per mailbox depending on connection. Bulk conversions of 20+ mailboxes are usually run overnight. The tool processes one folder at a time but supports queue-style multi-mailbox batches.