Univik Synology MailPlus Server Email Converter
Univik Synology MailPlus Server Converter reads standard MBOX email exports from MailPlus Server and converts them to PST, PDF, EML, MSG and other formats on your local Windows machine. Every account, folder, attachment and metadata field is preserved. No connection to the Synology NAS is required after the initial export.
*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 Synology MailPlus Server accounts when decommissioning NAS hardware or migrating to cloud email.
MailPlus Server Email 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
Labels
MailPlus Tags
Key Features
Built for IT administrators and system managers migrating away from Synology MailPlus or archiving historical accounts.
Once MBOX files are exported from MailPlus Server using the DSM interface, Univik Converter works entirely on your local Windows machine. No VPN, no NAS IP, no DSM login. This makes conversion practical when decommissioning a NAS, restoring from backup or working from a different site.
MailPlus Server organises emails into Inbox, Sent, Drafts, Trash and custom user-created folders. Univik Converter reads the full MBOX folder hierarchy and recreates it in the output. PST output mirrors the folder structure as Outlook folders. EML output creates matching directories. No emails are ever merged or flattened.
Export MBOX files for every MailPlus user account into a folder, then run Univik Converter once. Each account is processed in sequence and generates its own output file named after the account. For organisations with 50 or 500 accounts, this eliminates the manual effort of converting one account at a time.
All file attachments are extracted from the MBOX source 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 MBOX 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 Synology MailPlus 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 MailPlus 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
Export from the NAS, convert on Windows, import into your destination system.
In Synology DSM, go to MailPlus Server and use the mail export function to save user account mailboxes as MBOX files. Copy the exported files to a Windows PC via SMB share, USB or any file transfer method. Keep the folder structure intact for accurate account identification.
Alternatively, use the MailPlus web client PST export for individual accounts.
Open Univik MailPlus Converter. Browse to a single MBOX file or a folder containing multiple account exports for batch processing. Preview shows email counts, folder structure and date ranges for each account. Apply any date or folder filters needed before conversion.
Select output format and destination folder. Click Convert. Each account generates its own output file. Import PST files directly into Outlook or Microsoft 365 . Converting Synology MailPlus to Outlook is simpler this way takes one PST import after conversion. 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 MailPlus Converter.
When a Synology NAS reaches end of life or is replaced, IT teams need to preserve all MailPlus email accounts before powering down the hardware. Univik Converter processes the exported MBOX archive into PST or EML so all historical email remains accessible after the NAS is gone.
Organisations moving from Synology MailPlus 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 MailPlus accounts to PDF or EML creates a compliant, readable archive independent of the NAS infrastructure. 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 MailPlus mailbox before the account is deactivated. Univik Converter exports the departing employee's full account 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 MailPlus Server use Univik Converter to validate MBOX backup archives 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.
MailPlus Server Reference
What MailPlus Server is, how it stores email and what the conversion process involves technically.
Synology MailPlus Server is an on-premise email server package for Synology NAS devices running DSM 6.0 or later. It provides SMTP, POP3 and IMAP services, letting small and medium businesses run a fully managed email server on Synology hardware.
MailPlus Server stores all emails in standard MBOX format on the NAS filesystem. Since MBOX is an open standard, the data can be read by any MBOX-compatible tool once exported from the NAS. MailPlus MBOX to PST conversion is the most common operation after a Synology NAS email export.
| Developer | Synology Inc. (Taiwan) | |
| Platform | DSM 6.0 / 7.x | |
| Email storage | MBOX (standard Unix format) | |
| Protocols | SMTP, POP3, IMAP | |
| Built-in export | PST only (web client, NAS required) | |
| Current version | MailPlus 4.x (4.0 Beta 2026) | |
| License | Free for 5 accounts, paid beyond | |
| Official docs | Synology Knowledge Center | |
Synology MailPlus Version History
Synology started with a basic Mail Server package in DSM, then replaced it with the feature-rich MailPlus Server, adding high-availability clustering, the MailPlus web client, Bitdefender antivirus integration and admin-level export and audit tools.
Version Timeline
Why Univik
Univik has been building email archive converters since 2013. The MailPlus 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 MailPlus Server accounts.
"We decommissioned our Synology DS920+ and needed to export 12 user accounts from MailPlus. Converted all accounts to PST in under an hour. The folder structure was exactly preserved in Outlook."
"Needed to archive 5 years of MailPlus emails to PDF for a compliance audit. Batch converted 3 accounts with date filters. Each PDF has the full headers. Exactly what our auditor needed."
"Migrating our office from MailPlus to Microsoft 365. Converted 28 MBOX exports 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 Synology MailPlus Server email accounts.
Free trial. No NAS required. No registration. Your emails stay on your machine.
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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 Synology MailPlus Server email export and conversion, tested against real MailPlus MBOX exports from DSM 6 and DSM 7 environments. For professional email migration assistance, see our email migration service.
Related converters: Mail Assure | Mimecast | Google Vault | MailStore Server
Univik Synology MailPlus Server Email Converter
MailPlus Server Email Data Extracted
Data Integrity
Simple Pricing
How It Works
Use Cases
MailPlus Server Reference
Why Univik
Customer Reviews
FAQs