A 5-minute walkthrough of moving MDaemon Server mailbox data into a Gmail or Google Workspace account using the 4n6 MDaemon to Gmail Migration Tool. Useful for SMBs retiring on-premises MDaemon and going cloud-first with Workspace. If your destination is Microsoft 365 instead, see our MDaemon to Office 365 guide. If you only need a portable archive without cloud destination, see convert MDaemon emails.
Video Transcript
Hello and welcome. This video shows how to import MDaemon Server mailbox data to a Gmail or Google Workspace account. We use the 4n6 MDaemon to Gmail Migration Tool. MDaemon stores mail in a proprietary MSG plus MRK file format inside a Users directory. Each user mailbox lives at C:\MDaemon\Users\<domain>\<username>.
Step one. Generate a Gmail or Workspace app password for the destination account. Sign in to myaccount.google.com, click Security, ensure Two-Step Verification is on, then go to App passwords and create a 16-character password. Copy it.
Step two. Stop the MDaemon service briefly so the Users directory is not in flux during the copy. Copy the user folders from C:\MDaemon\Users\domain to a Windows workstation. Restart MDaemon.
Step three. Download and install the 4n6 MDaemon to Gmail Migration Tool.
Step four. Launch the tool. Click Open Configured MDaemon Data if MDaemon is on the same machine, otherwise Choose Folders and browse to the copied Users directory. The tool reads MSG and MRK files and shows the folder tree. Tick the folders to migrate.
Step five. From the Save As dropdown, pick Gmail or Google Workspace. Both options use imap.gmail.com on port 993 with SSL. Enter the destination Gmail address. Paste the 16-character app password.
Step six. Click Convert to start the migration. The tool uploads each message via IMAP. A live progress bar shows uploaded count. When complete, a Notepad log lists items migrated, items skipped and any errors. Verify by signing in to the Gmail account in a browser and checking that folders appear with the correct message count. Thanks for watching.
What This Migration Looks Like
Moving from MDaemon Server to Google Workspace is a common SMB email migration in India. MDaemon is a Windows-only mail server developed by MDaemon Technologies (formerly Alt-N Technologies, founded 1996), historically popular with Indian SMBs that wanted Exchange-style features without Exchange's licensing complexity. Workspace is Google's cloud productivity suite that bundles Gmail with Drive, Meet, Calendar and Docs.
The most common reasons to move from MDaemon to Workspace in 2026: consolidating to Google's cloud productivity stack, retiring on-premises Windows Server hardware that hosted MDaemon, eliminating MDaemon update and security patch management, getting modern collaboration features (shared calendars, distribution lists, Google Meet) that MDaemon's WorldClient interface cannot match, or because the company has been acquired and the parent runs on Workspace.
The tool used in this video is the 4n6 MDaemon to Gmail Migration Tool. It is a different product from the 4n6 MDaemon to Microsoft 365 Migration Tool (which targets Microsoft Exchange Online) and the 4n6 MDaemon Server Converter (which produces PST and other file outputs). Each is a separate product page on forensiksoft.com. Pick the one that matches your destination.
Why Gmail Migration Is Easier Than Microsoft 365
The single biggest difference between Gmail and Microsoft 365 as migration destinations is authentication. Microsoft permanently disabled IMAP basic authentication for Exchange Online in late 2022, so any tool writing to an M365 mailbox must use OAuth / modern authentication. Google kept the app password mechanism specifically for legacy clients and migration tools.
An app password is a 16-character one-time code that bypasses 2-Step Verification for a single application. It functions as the IMAP password. The migration tool sends username plus app password to imap.gmail.com on port 993 with SSL, and uploads work without browser-based OAuth flows or MFA prompts during the migration itself.
Practically this means: no per-user OAuth sign-in window during migration, no MFA timing coordination with each user, no Conditional Access policies blocking the tool, no Microsoft Entra app permissions to approve. The trade-off is that Workspace has stricter rate limits than Microsoft Exchange Online, so very large migrations can be slower in absolute terms. For most SMB migrations under 50 users and 100 GB total, the Gmail path is significantly simpler.
How MDaemon Stores Mail
MDaemon's storage model differs from most email servers. Each user has a folder of subdirectories with proprietary MSG files for messages, plus separate MRK container files for non-mail data. Understanding the layout helps the migration capture all data correctly.
| Component | Location and format |
|---|---|
| User mailbox root | C:\MDaemon\Users\<domain>\<username>\ |
| Mail messages | MSG files (MDaemon proprietary format, NOT Microsoft Outlook MSG) inside subfolders like INBOX, Sent, Drafts, Trash, custom user folders. Each .msg file is a single email. |
| Folder index files | Each mail subfolder contains .mrk companion files holding folder-level metadata: read flags, message ordering, message IDs. |
| Contacts | AddrBook.mrk, single MRK container holding all contacts as vCard-equivalent entries. |
| Calendar | Calendar.mrk, single container holding all calendar events. |
| Notes | Notes.mrk, single container of stored notes. |
| Tasks | TaskList.mrk, single container of tasks and to-dos. |
| Documents | Documents.mrk, for users who store personal documents inside MDaemon (less common). |
| IMAP state | .IMAP folder holds IMAP-specific metadata: subscribed folder list, UIDVALIDITY values, last-seen state. |
This layout matters because a basic file copy that grabs only the message folders will lose all calendar, contacts, notes and tasks data. Always copy the entire user folder, not just mail subdirectories. The 4n6 tool reads the .mrk container files automatically and writes them to the matching Workspace data type (calendar events to Google Calendar, contacts to Google Contacts, etc.).
Migration Path Options
For an MDaemon-to-Workspace project there are three realistic paths. Pick based on volume and operational constraints.
| Path | When to pick it |
|---|---|
| Direct cloud upload (this video) | Pick for small to mid-size migrations (under 100 GB total, under 50 users). Uses 4n6 MDaemon to Gmail Migration Tool. Reads MDaemon Users directory directly, uploads to Workspace mailboxes via IMAP with app password. Pros: simplest workflow, no PST intermediate, calendar and contacts handled in same pass via .mrk parsing. Cons: depends on stable internet through entire upload, Workspace IMAP rate limits. |
| PST intermediate + Workspace Data Migration Service | Pick for large migrations (100 GB+ or 50+ users) or when you want a portable archive copy too. First convert MDaemon to PST via the 4n6 MDaemon Server Converter. Then use Google's free Workspace Data Migration Service to import. Pros: archive copy preserved, can run upload separately. Cons: more administrative steps, DMS has 2,500 messages-per-user-per-session limit. |
| Workspace DMS with MDaemon as live IMAP source | Pick when MDaemon is still running and IMAP is enabled on the source. Configure MDaemon as IMAP source in admin.google.com > Data Migration. Pros: free, official Google path. Cons: doesn't migrate calendar (.mrk) or contacts (AddrBook.mrk), requires MDaemon's IMAP to be reachable from Google. |
Workspace Pre-Migration Checklist
The MDaemon side rarely has issues. The Workspace destination is where most migrations stumble. Work through this list before clicking Convert.
| Check | Why it matters |
|---|---|
| Workspace subscription active | Pick a plan that fits your storage needs: Business Starter (30 GB per user), Business Standard (2 TB per user), Business Plus (5 TB per user), Enterprise (5 TB+ per user). MDaemon mailboxes over 30 GB cannot fit on Business Starter. |
| Custom domain verified | Add yourcompany.com to Workspace at admin.google.com. Verify ownership via DNS TXT record. Domain must be verified before destination users can be created on that domain. |
| Destination users created with matching addresses | Create each MDaemon user as a Workspace user. Use the same email address as MDaemon (raj@yourcompany.com on MDaemon = raj@yourcompany.com on Workspace) so historical mail flow continues correctly after MX cutover. |
| Workspace license assigned per user | Each migrated user needs a Workspace license. License assignment creates the Gmail mailbox immediately, no provisioning delay like M365. |
| 2-Step Verification enabled per user | App passwords are gated behind 2FA. Without 2FA enabled on the destination Workspace user, the App passwords page does not appear. Enable at the user level via myaccount.google.com/security. |
| App password generated per destination user | One 16-character app password per destination Workspace mailbox. Copy each immediately, you cannot view it again later. Name them descriptively like "MDaemon Migration 2026 user@example.com". See our Gmail app password guide. |
| Workspace IMAP enabled | Workspace IMAP is on by default but can be disabled by an admin policy. Verify at admin.google.com > Apps > Google Workspace > Gmail > End User Access. IMAP must be on for the destination users to accept inbound migration uploads. |
| MDaemon Users directory copied off the live server | Stop MDaemon service via services.msc, copy C:\MDaemon\Users\<domain>\ to a Windows workstation, restart MDaemon. Reading the live Users directory while MDaemon is writing produces corrupt MSG/MRK reads. |
| Stable internet connection | Sustained upload over the network. 50 GB on 50 Mbps Indian residential broadband takes roughly 2.5 hours. Wired ethernet, not Wi-Fi, for stability through the full upload window. |
| MX records still pointing at MDaemon | Do NOT change MX records before migration completes. Mail flow stays on MDaemon so no incoming messages are lost. Cutover happens after verification. |
| Trial run with one user first | Migrate one volunteer user end-to-end. Catches issues with app passwords, .mrk handling, custom folder names, attachment size limits before they hit your bulk job. |
Tool Specifications
| Specification | Value |
|---|---|
| Tool name | 4n6 MDaemon to Gmail Migration Tool |
| Vendor | 4n6 Software (forensiksoft.com) |
| Pricing | $99 personal (2 PCs) / $299 business (10 PCs) / $499 enterprise (50 PCs) |
| Trial limit | 10 items per folder, free download |
| Operating system | Windows 7 / 8 / 8.1 / 10 / 11 (32 or 64-bit), Windows Server 2008 / 2012 R2 / 2016 / 2019. Migration tool is Windows-only. |
| Source MDaemon versions | MDaemon Server 12.x through 23.x. All recent MDaemon Email Server releases. |
| Source data access | Read access to MDaemon Users directory (default C:\MDaemon\Users\<domain>\). Local copy, network share or USB drive all work. Auto-detect feature when MDaemon is installed on the same machine. |
| Destination | Gmail (@gmail.com personal account, only when source is also a personal Gmail style address) or Google Workspace (custom-domain account, the typical SMB destination). |
| Destination authentication | 16-character Gmail/Workspace app password. Generated at myaccount.google.com/apppasswords after enabling 2-Step Verification. |
| File formats parsed | MSG (MDaemon proprietary), MRK, AddrBook.mrk, Calendar.mrk, Notes.mrk, TaskList.mrk, Documents.mrk, .IMAP folder contents. |
| Migration types supported | Emails, calendar events, contacts, tasks, notes, journals, attachments. Multi-user batch mode with CSV mapping. Selective folder migration. |
| RAM | 2 GB minimum, 4 GB recommended for large mailboxes |
| Internet | Required throughout the upload. Wired ethernet recommended. |
Gmail Destination IMAP Settings
The 4n6 tool uploads via IMAP to Google's servers. These are the settings the tool uses, worth knowing in case authentication fails.
| Setting | Value |
|---|---|
| IMAP server | imap.gmail.com |
| Port | 993 with SSL/TLS required |
| Username | Full destination email address (raj@yourcompany.com for Workspace, raj@gmail.com for personal) |
| Password | 16-character app password, NOT the regular Google account password |
| Authentication | PLAIN over SSL. The tool handles this automatically |
| Source documentation | Settings published by Google at Check Gmail through other email platforms. Same settings apply for Workspace. |
6 Steps to Import MDaemon to Gmail Account
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Generate a Gmail or Workspace app password. Sign in to the destination account at myaccount.google.com. Click Security. Ensure 2-Step Verification is on. Go to myaccount.google.com/apppasswords. Create a new app password named for this migration ("MDaemon Migration 2026"). Copy the 16-character code immediately. For multi-user migrations, generate one app password per destination user. See our Gmail app password guide for screenshots.
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Copy the MDaemon Users directory to a Windows workstation. On the MDaemon server, open services.msc and stop the MDaemon service so the Users directory is not in flux during the copy. Use robocopy to copy C:\MDaemon\Users\<domain>\ to your Windows workstation (robocopy verifies file integrity and resumes on failure, plain Explorer drag-and-drop can silently skip files). Restart the MDaemon service after the copy completes so users keep getting mail during the upload phase. Migration runs against the copy, not the live store.
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Install the 4n6 MDaemon to Gmail Migration Tool. Visit forensiksoft.com and download the installer. Install on the Windows workstation. The tool is standalone and does not require MDaemon, Outlook or any Google client to be installed. Trial version migrates 10 items per folder so you can verify the workflow before buying a license.
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Load MDaemon mailbox and select folders. Open the converter. If MDaemon is installed on the same machine, click Open Configured MDaemon Data for auto-detection. Otherwise click Choose Files or Choose Folders and browse to the copied Users\<domain>\<username>\ directory. The tool reads MSG files, MRK container files (AddrBook.mrk, Calendar.mrk, Notes.mrk, TaskList.mrk, Documents.mrk), and the .IMAP folder. Folder tree appears on the left panel. Tick the folders to migrate. Use the preview pane (Hex, Raw, Headers view modes) to inspect individual messages.
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Pick Gmail and enter app password. From the Save As dropdown, pick Gmail or Google Workspace (both options route through imap.gmail.com). Enter the destination email address. Paste the 16-character app password from step 1. For multi-user migrations, tick I am converting Multiple Users and provide a CSV file mapping source mailbox folder paths to destination email addresses with their per-user app passwords.
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Click Convert and verify in Gmail. Click Convert. The tool uploads each parsed message to imap.gmail.com port 993 SSL using the app password. Calendar events from Calendar.mrk go to Google Calendar, contacts from AddrBook.mrk go to Google Contacts, tasks from TaskList.mrk go to Google Tasks. A live progress bar shows uploaded count per data type. When complete, a Notepad log lists items migrated, items skipped and any errors. Sign in to the destination account at mail.google.com and verify each data type.
Common Errors and Fixes
| Error or symptom | Cause and fix |
|---|---|
| "Invalid credentials" / authentication failed | You used the regular Google account password instead of an app password. Or the app password was copied with a trailing space. Or 2FA was disabled on the destination account, which silently invalidates app passwords. Generate a fresh app password and paste carefully into the tool. The 16-character format has no spaces (the spaces shown by Google in the display are visual separators only). |
| "Cannot read MSG file" or "Invalid MSG header" | The MDaemon Users directory was copied while MDaemon was still running and writing to a file. Stop MDaemon service, re-copy that user's folder, retry. Alternatively the MSG file is genuinely corrupt, so skip it and check the MDaemon server logs for delivery errors around its timestamp. |
| "Access for less secure apps" warning | Outdated. Google removed the Less Secure Apps setting in May 2022. App passwords are now the only IMAP login path for accounts with 2FA. If you see "less secure apps", the documentation is stale, just use the app password. |
| Upload starts then stalls after a few hundred messages | Hit Gmail's rate limit. Workspace allows roughly 10,000 IMAP messages per day per user. Personal Gmail allows less. The tool throttles automatically and resumes, but may pause for several minutes between batches. Run overnight for large mailboxes. |
| Folders appear in Gmail but with zero messages | The tool created the folder structure via IMAP CREATE but the actual upload of message bodies failed silently. Check the conversion log for skipped items. Often caused by a single malformed MSG file in MDaemon causing the parser to abort. Skip the corrupt file and re-run. |
| Calendar.mrk events appear as plain emails in Inbox | The tool wrote calendar items as mail messages instead of detecting them as calendar source. Re-run conversion separately for Calendar.mrk with output set to ICS, then import the ICS file into Google Calendar at calendar.google.com > Settings > Import & Export. Same approach for AddrBook.mrk: re-export to vCard, import to Google Contacts. |
| "Message size exceeds 25 MB" | Gmail's per-message size limit is 25 MB for messages received via IMAP / SMTP, and 35 MB for the IMAP upload protocol itself. MDaemon MSG files with attachments larger than this skip silently. Check the conversion log for "size exceeded" entries. For these messages, extract the attachments separately and upload via Google Drive with a sharing link in the email body. Note: this is far stricter than Microsoft 365's 150 MB limit. |
| Workspace storage full | Workspace Business Starter has 30 GB per user. If a user's MDaemon mailbox exceeds this, the migration cannot complete on Starter. Upgrade to Business Standard (2 TB) or Plus (5 TB) for that user, or reduce data via date filters in the migration tool to only move recent mail. |
| Custom domain destination rejects upload | Workspace domain not yet verified, or the destination user not yet licensed. Sign in to admin.google.com, verify the domain via DNS TXT record, assign a Workspace license to the destination user, then retry the migration. |
| Connection drops mid-migration | Indian residential broadband often has 5-30 second drops on Wi-Fi. Use wired ethernet. If drops continue, split migration into per-folder batches. Smaller batches mean smaller restarts. |
Gmail vs Microsoft 365 as Destination (Quick Reference)
If you are deciding between Workspace and M365 for an MDaemon migration, here are the practical destination differences. Both are excellent destinations, the choice depends on what the rest of your stack uses.
| Aspect | Gmail / Workspace (this video) | Microsoft 365 (companion guide) |
|---|---|---|
| Authentication for migration | App password (16-character code) | OAuth / modern auth (browser sign-in with MFA) |
| Per-message size limit | 25 MB receive, 35 MB IMAP upload | 150 MB |
| Default mailbox quota | 30 GB Starter / 2 TB Standard / 5 TB Plus | 50 GB Business / 100 GB E3+ |
| IMAP rate limit | ~10,000 messages per user per day | Per-mailbox connection and message rate limits, throttling kicks in earlier |
| Free server-side migration tool | Workspace Data Migration Service (2,500 messages/user/session) | Microsoft Network Upload (PST upload via Azure) |
| MX endpoint | ASPMX.L.GOOGLE.COM + ALT1-4 (5 records) | <tenant>.mail.protection.outlook.com (1 record) |
| Conditional Access concerns | Rare for SMBs, only enterprise customers | More common in enterprise tenants, can block migration tools |
| Migration tool product | 4n6 MDaemon to Gmail Migration | 4n6 MDaemon to Microsoft 365 Migration |
| Best for | SMBs already using Google Drive / Meet / Calendar, simpler auth model preferred, smaller per-user storage needs | SMBs already using Microsoft Office / Teams / OneDrive, larger per-message attachments common, deeper enterprise security policies |
MX Record Cutover to Workspace
The mail-flow cutover from MDaemon to Workspace.
| Phase | What happens |
|---|---|
| Before migration | MX records point to MDaemon. All mail flows to MDaemon. Migration tool uploads historical mail to Workspace mailboxes in parallel. No mail flow change yet. |
| Migration in progress | Run the 4n6 MDaemon to Gmail Migration Tool for all users. Mail still flowing to MDaemon. Plan for a Friday-night start so it finishes by Sunday. |
| Verification phase | Sign in to each destination Workspace mailbox at mail.google.com. Verify message count, folder structure, calendar events in Google Calendar, contacts in Google Contacts. Have each user verify their own mailbox if possible. |
| MX cutover | Update DNS MX records at your registrar. Set the primary MX to ASPMX.L.GOOGLE.COM with priority 1, plus the four secondary MX records (ALT1.ASPMX.L.GOOGLE.COM through ALT4.ASPMX.L.GOOGLE.COM) per Google's official Workspace MX setup. Set TTL to 300 seconds a day before for fast propagation. |
| Cutover window | For 24-48 hours after MX change, mail can land at either MDaemon or Workspace as DNS propagates. Configure MDaemon to forward all incoming mail to the Workspace domain so nothing is lost during the propagation gap. |
| Post-cutover | Keep MDaemon running read-only for 30-90 days as a safety net. Decommission MDaemon Server once you're confident no missed mail remains. |
Tool Comparison: MDaemon to Gmail Migration Options
| Tool | Notes |
|---|---|
| 4n6 MDaemon to Gmail Migration Tool (this video) | Direct cloud upload via IMAP with app password. $99 personal / $299 business / $499 enterprise. Trial: 10 items per folder. Windows only. Sister products: 4n6 MDaemon Server Converter (PST output), 4n6 MDaemon to Microsoft 365 Migration (M365 destination), 4n6 MDaemon to IMAP Migration (generic IMAP destination). |
| Google Workspace Data Migration Service (free) | Free, included with Workspace. Configured at admin.google.com > Data Migration. Supports IMAP source. Pros: free, official Google. Cons: 2,500 messages-per-user-per-session ceiling per Google's DMS documentation, requires live MDaemon with IMAP enabled, doesn't migrate calendar (.mrk) or contacts (AddrBook.mrk). |
| RecoveryTools MDaemon Migrator | Similar pricing range. Cloud destination support including Workspace, M365, Yahoo, Outlook.com. Trial: 25 items per folder. Windows only. |
| BitRecover MDaemon Converter | ~$89 starter price. 25+ saving formats including direct Workspace upload. 30-day money-back guarantee. |
| SysTools (no dedicated MDaemon-to-Gmail product) | SysTools does not ship a dedicated MDaemon to Gmail migration tool. Their SysTools IMAP Migration tool can be used when source MDaemon is live with IMAP enabled. Cleaner option is to use a vendor with native MDaemon MSG/MRK parsing. |
Real Migration Scenarios
| Scenario | Approach and notes |
|---|---|
| SMB retiring on-premises MDaemon, 20-50 users to Workspace Business Standard | The most common case in Indian SMBs. Total Users data 30-200 GB. Direct cloud upload with the 4n6 MDaemon to Gmail tool. Plan one weekend of upload. Generate per-user app passwords in advance, stored in a password manager so you don't lose them. |
| MDaemon Connector for Outlook users moving to Workspace | Shops that use MDaemon Connector for Outlook (the proprietary plugin that gives MDaemon Exchange-like features) often have rich calendar usage. The 4n6 tool migrates calendar via Calendar.mrk to Google Calendar, contacts via AddrBook.mrk to Google Contacts. Users get a different experience in Workspace (Gmail interface vs Outlook), so factor in user training. |
| Domain rebrand: MDaemon on oldcompany.com, Workspace on newcompany.com | Map source mailbox to destination email via the tool's CSV mapping. For each user, the CSV row maps oldcompany.com source folder to new@newcompany.com destination. Set up email aliases in Workspace so old@oldcompany.com still routes to new@newcompany.com during the transition. |
| Hybrid period: phased user migration over weeks | Migrate IT and management first as pilot. Verify Workspace setup works end-to-end. During hybrid period, set MDaemon to forward mail for migrated users to their Workspace addresses. Roll out remaining users in batches. MX cutover happens after everyone migrates. |
| Departed-employee archive into shared Workspace mailbox | When an employee leaves, migrate their MDaemon mailbox into a shared Workspace inbox kept by HR. Use the CSV mapping feature to point all source folders at the shared destination. Allows compliance access without paying for a per-user license long-term. |
| Hosted MDaemon by managed service provider | If your MDaemon is hosted by an MSP with no file-system access to the Users directory, fall back to the Workspace Data Migration Service path (admin-driven, IMAP server-to-server). Calendar and contacts won't migrate this way, handle separately by exporting from MDaemon WorldClient and importing to Google Calendar / Contacts. |
| MDaemon to G Suite Legacy (existing free accounts) | The free G Suite Legacy edition was discontinued for new signups in 2012 but existing accounts continued until 2022. If you still have a legacy free Workspace, migration steps are identical, but storage limits are tighter (15 GB per user vs Workspace Business 2 TB). Verify quota before migration. |
đź’ˇ Pro tips for MDaemon to Gmail migrations
- Run migration before MX cutover, not after. Mail flow stays on MDaemon during migration so historical mail uploads while no new mail is lost. Cut over MX only after verification.
- Make sure .mrk container files are included in the copy. A simple mail-folder-only copy misses Calendar.mrk, AddrBook.mrk, Notes.mrk, TaskList.mrk and loses all non-mail data. Copy the entire user folder, not just the mail subdirectories.
- Generate app passwords in advance and store them securely. Once you click Done on the App passwords page, the 16-character code is gone forever. Use a password manager. Name each one descriptively like "MDaemon Migration 2026 user@example.com".
- Use robocopy or rsync for the Users directory copy. Both verify integrity and resume on failure. Plain Explorer drag-and-drop can silently skip files on permission errors.
- Wired ethernet on the migration workstation. Sustained IMAP uploads to Gmail are sensitive to connection drops. Indian Wi-Fi on residential broadband often has 5-30 second outages that break the session.
- Watch for the 25 MB attachment limit. Gmail rejects messages over 25 MB. MDaemon often holds larger attachments because MDaemon admins set higher limits than Gmail. Check the migration log for "size exceeded" entries and handle those messages manually with Google Drive sharing links.
- Plan storage upgrades before migration if needed. Workspace Business Starter has 30 GB per user. If any MDaemon user mailbox exceeds this, upgrade to Business Standard (2 TB) for that user before migration starts, otherwise the migration will hit quota mid-upload and fail unpredictably.
- Schedule for off-hours. Most Indian SMBs prefer Friday-night start so the upload runs over the weekend and Monday morning users are on Workspace. Avoid Monday or Tuesday cutovers, you have less time to fix issues before the working week ramps up.
- Revoke app passwords after migration completes. After verification, go to myaccount.google.com/apppasswords and revoke each migration app password. Leaving them active is a credential sitting around for no reason.
- Forward MDaemon mail to Workspace during MX propagation. Configure MDaemon to send a copy of all incoming mail to user@yourcompany.com (the Workspace mailbox) during the 24-48 hour DNS propagation window. This guarantees no messages are missed regardless of which server DNS resolution lands on.
- Keep the MDaemon Users directory for 90+ days. If a user reports missing email after migration, you can re-extract from the original.
- If your destination is Microsoft 365 instead, use the MDaemon to Office 365 guide. Different OAuth flow, different rate limits, different MX records.
- If you only need a PST archive without cloud destination, see our convert MDaemon emails guide.
Frequently Asked Questions
Why is a third-party tool needed for MDaemon to Gmail migration?
MDaemon stores mail in a proprietary MSG plus MRK file format. Gmail and Google Workspace only accept mail via standard protocols (IMAP, Gmail API). There is no native MDaemon export feature that produces a Gmail-compatible format directly. A migration tool reads MDaemon's proprietary files and uploads them to the Gmail mailbox via IMAP. The 4n6 MDaemon to Gmail Migration Tool handles this in one pass, including the .mrk container files for calendar and contacts.
Personal Gmail or Google Workspace as destination?
For migrating a custom-domain MDaemon mailbox (yourname@yourcompany.com), the destination must be a Google Workspace account on the same custom domain. Personal Gmail (@gmail.com) does not accept inbound IMAP imports for custom-domain mail. If the source MDaemon account is already on @gmail.com style addresses (rare for MDaemon), personal Gmail works. For Indian SMB MDaemon deployments, Workspace is almost always the realistic target.
Where does MDaemon store mailbox data?
MDaemon stores each mailbox under C:\MDaemon\Users\<domain>\<username>\ on the MDaemon server. Inside each user folder are mail subfolders (INBOX, Sent, Drafts, custom folders) containing MSG files, plus special MRK container files: AddrBook.mrk for contacts, Calendar.mrk for calendar events, Notes.mrk for notes, TaskList.mrk for tasks, Documents.mrk for stored documents. The .IMAP folder holds IMAP-specific state. MDaemon is Windows-only.
Why does Gmail still allow app passwords when Microsoft 365 doesn't?
Google and Microsoft made different decisions about basic authentication for IMAP. Microsoft permanently disabled IMAP basic auth in Exchange Online for all tenants in late 2022, requiring OAuth/modern authentication for any IMAP write to an M365 mailbox. Google kept the app password mechanism specifically for legacy clients and migration tools that don't support OAuth. App passwords are 16-character one-time codes that bypass 2-Step Verification for a single application. They work as the IMAP password for both personal Gmail and Google Workspace destinations.
What are Gmail and Workspace IMAP migration limits?
Personal Gmail allows roughly 35 MB upload per IMAP session and a few hundred messages per minute. Workspace permits higher quotas, around 10,000 IMAP messages per day per user. Google's official Workspace Data Migration Service (DMS) has a 2,500 messages-per-user-per-session ceiling. The 4n6 tool does not use DMS; it uploads directly via IMAP. For large mailboxes (10,000+ messages), expect 30 minutes to several hours per user, run overnight if needed.
Should I migrate or change MX records first?
Migrate first, change MX records last. Run the migration tool while MDaemon is still receiving mail so no incoming messages are lost. Verify all historical mail has uploaded to Workspace mailboxes. Only after verification, schedule a maintenance window to update DNS MX records pointing to Google's MX servers (ASPMX.L.GOOGLE.COM and the secondary records ALT1 through ALT4). DNS propagation typically takes 1-4 hours.