Univik TerraMaster Mail Server Converter
Univik TerraMaster Converter reads the mailbox files stored by the TerraMaster NAS Mail Server and converts them to PST, PDF, EML, MSG and other formats on your local Windows machine. Every mailbox, folder, attachment and metadata field is preserved. No connection to the TerraMaster NAS is required after you copy the mail folder.
*Free trial converts the first 25 emails per folder. No registration required.
Trusted for NAS Email Migration
IT administrators and system managers use Univik to export and archive TerraMaster mail server mailboxes when decommissioning NAS hardware or migrating to cloud email.
Mail Server Data Extracted
From
Sender
To
Recipients
Subject
Email Title
Date
Timestamp
Body
Full Content
Attachments
All Files
CC / BCC
All Recipients
Folders
Full Hierarchy
Message-ID
Unique ID
Headers
All RFC Headers
HTML Body
Rich Content
Flags
IMAP Flags
Key Features
Built for IT administrators and system managers migrating away from a TerraMaster mail server or archiving historical mailboxes.
Once the mailbox folders are copied off the TerraMaster NAS using File Manager, an SMB share or the Docker volume, Univik Converter works entirely on your local Windows machine. No VPN, no NAS IP, no TOS login. This makes conversion practical when decommissioning a NAS, restoring from backup or working from a different site.
A Maildir mailbox keeps Inbox, Sent, Drafts, Trash and custom folders as separate directories. Univik Converter reads the full folder hierarchy and recreates it in the output. PST output mirrors the structure as Outlook folders. EML output creates matching directories. No emails are ever merged or flattened.
Point Univik Converter at the mail folder containing every account and run it once. Each mailbox is processed in sequence and generates its own output file named after the mailbox. For organisations with 50 or 500 users, this eliminates the manual effort of converting one mailbox at a time.
All file attachments are extracted from the mailbox files and embedded in the output. Email metadata including From, To, CC, BCC, Subject, Date, Message-ID and all RFC 5322 headers are preserved exactly as stored. No attachment is lost and no header is stripped during conversion.
Convert only emails within a specific date range, from specific folders or matching a subject keyword. Filters let you extract only the legally required emails for a compliance request or only the last six months of a departing employee's inbox rather than their entire seven-year email history.
Business email archives contain highly sensitive communications. Univik Converter processes every mailbox file locally on your Windows machine. No emails are transmitted to any server, no cloud processing occurs and no internet connection is required. The conversion log records every file processed for internal audit purposes.
Export Formats
Every format available for converting your TerraMaster mail server email archive. Import into a new mail system, archive for compliance or open in any email client.
Email Client Formats
Document and Archive Formats
Web and Structured Formats
All 20+ formats available in the full version. View the complete format list on the Univik Email Converter page.
Data Integrity
Every element of your TerraMaster mail server email data is carried through the conversion process without modification.
Simple Pricing
One-time payment. Lifetime license. No subscription. Free updates included.
How It Works
Copy the data off the NAS, convert on Windows, import into your destination system.
On the TerraMaster NAS, locate the mail server data directory that holds each account's Maildir mailbox. Copy these folders to a Windows PC via File Manager, an SMB share or the Docker volume. Keep the folder structure intact for accurate mailbox identification.
A Maildir mailbox stores each message as an individual file inside its new, cur and tmp folders.
Open Univik TerraMaster Converter. Browse to a single mailbox folder or the full mail directory for batch processing. Preview shows message counts, folder structure and date ranges for each mailbox. Apply any date or folder filters needed before conversion.
Select output format and destination folder. Click Convert. Each mailbox generates its own output file. Import PST files directly into Outlook or Microsoft 365. Move EML files into Thunderbird or any IMAP server. Send PDF archives to your compliance storage.
Use Cases
The organisations and IT teams that rely on Univik TerraMaster Converter.
When a TerraMaster NAS reaches end of life or is replaced, IT teams need to preserve all mail server mailboxes before powering down the hardware. Univik Converter processes the copied Maildir archive into PST or EML so all historical email remains accessible after the NAS is gone.
Organisations moving from a TerraMaster mail server to Microsoft 365, Google Workspace or another cloud mail platform need their historical emails in PST or EML format for upload. Univik Converter produces import-ready output for all major cloud migration tools without any intermediate reformatting step.
Regulated industries must retain business email for three to seven years. Converting the TerraMaster mailboxes to PDF or EML creates a compliant, readable archive independent of the NAS. Each PDF email record includes all headers and metadata required for audit trail and legal disclosure purposes.
When employees leave, IT managers need to archive their TerraMaster mailbox before the account is removed. Univik Converter exports the departing employee's full mailbox including sent items, drafts and any custom folders to PST or EML for handover to their manager or storage in the compliance archive.
Organisations running a TerraMaster mail server use Univik Converter to validate mailbox backups by converting them and verifying email integrity. Converting to EML or PST and spot-checking emails confirms that the backup is readable and complete before a real disaster makes this question urgent.
Mail Server Reference
What the TerraMaster mail server is, how it stores email and what the conversion process involves technically.
TerraMaster is a network storage brand whose TOS operating system can run a mail server on the NAS. On older TOS releases the Mail Server is an Application Center app backed by a MySQL database for accounts and domains. On TOS 5 and later many users run a standard Postfix and Dovecot stack in Docker instead.
Either way the mail server is a standard Linux stack that stores messages on disk in Maildir or mbox format. Since both are open standards, the data can be read by any compatible tool once the mail folder is copied off the NAS. TerraMaster to PST conversion is the most common operation after a TerraMaster NAS email export.
| Developer | TerraMaster (Shenzhen, China) | |
| Platform | TerraMaster NAS (TOS) and Docker | |
| Email storage | Maildir or mbox files on disk | |
| Protocols | SMTP, POP3, IMAP | |
| Account database | MySQL (accounts and domains) | |
| Built-in export | None (IMAP / webmail access only) | |
| Setup | TOS Mail Server app or Postfix and Dovecot | |
| Official docs | TerraMaster Support | |
TerraMaster Mail Server Background
TerraMaster shipped a Mail Server app in the TOS Application Center, backed by a MySQL database for accounts and domains. With TOS 5 the bundled app was retired, so many owners now run a standard Postfix and Dovecot stack in Docker. Both keep messages on disk in Maildir or mbox format.
Deployment Timeline
Why Univik
Univik has been building email archive converters since 2013. The TerraMaster converter is part of a comprehensive email archive toolkit that covers Mail Assure, Mimecast, Google Vault and 20+ other email archive formats.
Customer Reviews
Rated 4.8 out of 5 by verified users including system administrators and IT managers who converted TerraMaster mail server mailboxes.
"We decommissioned our TerraMaster F4-423 running the mail server and needed to export 12 mailboxes. Converted all of them to PST in under an hour. The folder structure was exactly preserved in Outlook."
"Needed to archive 5 years of mail server email to PDF for a compliance audit. Batch converted 3 mailboxes with date filters. Each PDF has the full headers. Exactly what our auditor needed."
"Migrating our office from the TerraMaster mail server to Microsoft 365. Converted 28 mailboxes to PST over a weekend. Imported directly into Exchange Online without any reformatting. Saved us two days."
FAQs
Answers to what IT administrators ask most about converting TerraMaster mail server mailboxes.
Free trial. No NAS required. No registration. Your emails stay on your machine.
Windows 7, 8, 10, 11 | 100% offline | 30-day money-back guarantee
Written by Univik Research Team
The Univik Research Team has been building email archive conversion software since 2013. Our engineers work with MBOX, PST, EML, MSG and all major email archive formats. This page covers TerraMaster NAS mail server export and conversion, tested against real Maildir mailboxes copied from TerraMaster TOS and Docker deployments. For professional email migration assistance, see our email migration service.
Related converters: Mail Assure | Mimecast | Google Vault | MailStore Server
Univik TerraMaster Mail Server Converter
Mail Server Data Extracted
Data Integrity
Simple Pricing
How It Works
Use Cases
Mail Server Reference
Why Univik
Customer Reviews
FAQs