Secure Your Business Mail Services

Construct a business-grade mail server with Synology MailPlus and stay connected with all your important emails anytime, anywhere.

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Technical Specifications

Reliable self-hosted mail service with greater value for money

One-time cost

You just need one quote to have all the required hardware and software in hand.

Grow with your business

Start small and upgrade the server without hassle when needed.

OpenPGP encrypted

The support of streamlined email encryption standard provides end-to-end encrypted communication for all major platforms, such as Gmail, Thunderbird, and Outlook.

Content Scan

Enable Content Scan and MCP (Message Content Protection) to take pre-defined actions on dangerous or sensitive email content.

Create a high-availability (HA) cluster for MailPlus Server to have the secondary server assume all workloads when one is under an unexpected event or hardware replacement.

Getting started is easy

Set up a mail service for your business within a few clicks.

Your own domain, one or multiple - Set up your custom domain and manage multiple email domains in one centralized email server.
Seamless migration from Microsoft Exchange/G Suite with the instructional wizard. You can even migrate emails from Gmail account without collecting employees’ credentials.
Compatible with nearly all mail clients using SMTP/IMAP/POP3 protocols, minimizing the barriers of transferring from previous mail service to MailPlus.
Windows AD/LDAP support to fit perfectly into the original IT environment. If you don’t have one, simply install Synology Directory Server.

Facilitating maintenance

Mitigate maintenance efforts by delegating administration and policy configurations.

Management delegation for associate administrators to help manage MailPlus Server and further reduce IT manager’s workload.
Unlimited aliases and group lists to improve the overall communication efficiency without purchasing extra licenses.
Customize user and group policies on their login methods, daily email traffic, and mail delivery, and configure global rules to filter unwanted emails and allow through important ones.

Keep your business GDPR-compliant

Effectively manage data retention and erasure to meet GDPR requirements.

Mail Search

Data protection officers can be authorized to search and preview email content, and further decide whether to export or delete the requested emails.

Administration Log

All search queries will be well-logged with detailed information, including username and login IP to prevent any possible abuse of Mail Search.

Internet threats have nowhere to hide

Defend against malicious attacks with full-fledged security features.

Protect the mail service against malware with Google Safe Browsing and industry-standard antivirus engines.
Detect spam with the high-performance engine Rspamd, and learn from user-reported spam for more precise detection.
Visualize threat statistics of inbound and outbound emails with clear diagrams.

Minimize barriers for your employees

No need to change users’ original habits with a boost in email management efficiency.

Cross-platform email access

Access emails with webmail from browsers or mail clients such as Outlook, Thunderbird, or Apple Mail, or with MailPlus on iOS and Android on the go.

Categorize your emails with ease

Use labels or mailbox folders to categorize your emails and create filters to auto-categorize them in your own way.

Stay focused on what’s important

Customize the priority mailbox to focus on important messages, or share your mailbox with your team to track progress on projects or tasks.

More than just a mail server

Install packages you need and turn the mail server into a communication platform.

Chat - The instant messaging service fully integrated with MailPlus allows you to chat before sending an email.
Calendar - Create an event directly from the email to Synology Calendar via the detected date/time format or the whole email.
To-do list - Add tasks to the Calendar to-do list when an assignment comes from emails.
File Station - Email file attachments directly from the same server or save inbound attachments to the server.

What’s more for your business mail service

Get the most out of your mail server.

Achieve more value for money with Business File Server. Learn more
Back up your emails with Shared Folder Sync. Learn more
Download the administrator’s guide. Learn more

Synology MailPlus

Synology MailPlus Server

Features

Privately-owned mail service on a Synology NAS, providing multiple domain centralization management, user policy, and mail logs for easy management
Cross-platform mail solution for accessing emails on a computer and a mobile device
Full-fledged security features for the defense against malicious attacks: Rspamd anti-spam mechanism, spam auto-learning, ClamAV anti-malware, and advanced SMTP security
High-availability cluster for an uptime mail service during system updates and hardware replacements via switching the mail system to the paired server in seconds
Seamless mail migration tool designed for Gmail, G Suite, Microsoft Exchange, Yahoo, and other IMAP servers

Specifications

Monitoring
- Outgoing emails sent, resent or unable to be sent from your Synology MailPlus Server, and incoming emails received or rejected by your Synology MailPlus Server
- Real-time server information including high-availability cluster status
- Statistics of various kinds of email threats presented by graphs
- Statistics of blocked inbound and outbound emails respectively, along with top senders/recipients of such emails
Management
- Multiple domain management and configuration settings related to alias, auto BCC, usage limit, and disclaimer in Synology MailPlus Server
- SMTP authentication that forces clients to provide user credentials for login when connecting to Synology MailPlus Server via SMTP
- SMTP settings and diverse policies for blocking emails which exceed the limit: hostname, SMTP banner, the maximum number of recipients per email, the maximum number of email hops, and the maximum size per email for Synology MailPlus Server
- External postmaster that is set to receive system emails sent to Mailer-daemon and Postmaster aliases from other mail servers
- Mail delivery settings that allow sending emails through other mail servers so that mail contents will not be exposed to the Internet and subject to possible attacks
- Synology MailPlus as a relay server that sends emails for servers listed on the trusted list, and receives emails listed on the domain list
- Blacklist and whitelist that can be set to reject, discard, or allow certain emails based on various criteria
- Connection policies that block emails sent from senders from unidentifiable domains and hosts that cannot be identified or may cause Synology MailPlus Server to be overloaded
- Communication between Synology MailPlus Server and external mail servers/third-party clients via SMTP, POP3, and IMAP protocols
- High-availability cluster that maximizes mail service uptime during system updates and hardware replacements via switching the mail system to the paired server in seconds
Security
- Custom spam filtering rules for scanning and blocking allow auto-learning from reported spam to achieve accurate detection
- DNSBL (DNS-based Blackhole List) filters out spam published through the Internet Domain Name Service (DNS) based on a list of IP addresses of computers or networks
- Greylist function returns a temporary error to mail clients
- Antivirus engines ClamAV and McAfee (paid option) scan all the incoming and outgoing emails for viruses. When an email is found infected, the system will delete/quarantine the email and send notifications to the related recipients
- ClamAV antivirus engine databases such as Google SafeBrowsing database or a third-party database help detect malicious links in emails
- Virus definitions will be automatically updated by the custom schedule
- Authentication mechanisms, such as SPF verification, DKIM verification, and DMARC, validate inbound emails and reduce spam
- Emails with potentially dangerous elements will be filtered after scanned by content and attachment file types
- MCP (Message Content Protection) rules can be applied to filter or block the targeted emails. If an email is matched with the rule's criteria, the rule score will be the total sum of the MCP score. If the total MCP score exceeds the MCP threshold score you defined, the mail system will execute the action you have selected from the following: Save to quarantine, Deliver anyway, Delete mail, Notify sender, or Forward
Auditing
- Displays logs of the mail queue for users to view the status of emails and to manipulate emails in the queue
- Displays logs regarding incoming/outgoing emails through your Synology NAS
- Displays administration logs to record setting changes made by administrators
- Allows keyword search for deleting or exporting emails
- Forwards logs to another server to back them up or transfers logs to a syslog server for centralized management
- Tracks the mail system/traffic and sends logs periodically
Mail Migration
- Seamless migration tools for migrating from Gmail, G Suite, Microsoft Exchange, Yahoo, and other IMAP servers (Supports reusing system configurations from Microsoft Exchange for quick system replacement)
- Multiple tasks for mail migration from external mail servers: custom filters for bypassing spam emails, emails received after user-defined date, and emails exceeding the maximum size limit (KB)
- Mail migration without access permissions of each source account for Microsoft Exchange users with the delegated account
Sizing
- Recommended number of users: up to 1,800*
- Recommended number of emails processed per day: up to 4,773,000*

Note

The number of users and emails processed per day may differ among Synology NAS models. Refer to the product specification for each NAS model's recommended number
You can also refer to the Synology MailPlus License page for details

Limitations

Only models with 512MB RAM or more can automatically update virus definitions

Features

An intuitive and powerful webmail client designed for organizing emails, and sharing mailboxes with work partners
User interface like three-column mode and the option for conversation view to better fit user's familiar experience
Custom filters and priority mailbox for effective mail management
MailBox sharing with other users for email centralization of a specific project
A hub of communication and schedules with its seamless integration with Synology Chat and Synology Calendar

Specifications

Compose
- Auto-complete list based on recipient email addresses saved in Contacts
- Auto-saved drafts
- OpenPGP for encrypting/signing emails
- Send cancellation period of 5, 10, 15, 20, or 30 seconds
- User-defined text styles: font styles, font sizes, and colors
- Auto-reply/forward based on user settings
Mail Management
- Centralizes management with a priority mailbox collecting emails from various mailboxes or labels
- Filters emails with custom exception rules for email organization
- Allows sorting emails by starring, archiving, moving to customized mailboxes, as well as adding labels
- Allows sharing the mailbox with internal users/groups to centralize emails over a specific project. Specific access permission to the shared mailbox can be assigned to each user/group
- Allows archiving mailbox to make all the archived emails appear in this mailbox
- Provides two columns and three columns for the split pane mode. There are further format options for two columns: one line without preview, one line with preview and two lines
- Provides a universal search bar with syntax operators to help find specific emails quickly and easily
- Gives flexible options for the display of external images: to always display external image from and to ask before displaying. The latter option prevents malicious senders from exploiting externally linked images
- Sends push notifications with a browser extension (optional)
- Displays emails in conversation mode or individual message mode. In conversation mode, a single email will be grouped with all its replies
General Settings
- Signature setup for outgoing emails with various format tools (e.g., font size, color, and image insertion)
- Restores a conversation mistakenly identified as spam
- Allows adding additional SMTP servers or editing existing ones according to one's preference for email. For example, you can add the Google SMTP server and enter your Google account and password to send emails via Google account in Synology MailPlus
- Customizable POP3 servers and predefined ones (e.g., Gmail) for fetching emails from different servers to Synology MailPlus
Administrator
- Allows users to receive emails from external POP3 mail servers
- Allows users to share links for large attachments
- Allows users to set OpenPGP to encrypt/sign emails
- Allows users to customize the logo in Synology MailPlus web portal
Integration
- Integrates with Synology Chat and Synology Calendar, serving as a hub of communication and schedules. With the plug-ins of Synology Chat and Synology Calendar, users can dive into project discussions and add emails to your to-do list right from Synology MailPlus
- Adds conversation to Synology Calendar tasks

Limitations

The "Administrator Settings" tab is visible only when users sign in with an admin account

Synology MailPlus Mobile

Features

Intuitive user interface for composing mails, receiving mails, and managing mails across Android or iOS devices
Labels and user-defined mailboxes for custom mail organization
Multiple templates, various built-in stickers and emoji for a quick reply
Contacts sharing in the account system for a quick selection of senders/recipients
Mobile signatures created in mobile Synology MailPlus

Specifications

Email management
- Conversation view for intuitive mail browsing
- Easy ways to keep mailboxes organized: apply labels, move to a certain mailbox, and mark as starred/read/unread
- Localized email address to send emails with or receive emails from email addresses in native languages (e.g., Chinese and Russian)
- Swipe gestures for moving across the next or previous email thread
- Actions on email notifications: delete, archive, and mark as read
- Undo operations for the labeled actions: delete, move, archive, and remove
- Mail printing in a thread
- Image viewer for viewing attached images without downloading
- Manual events adding to Synology Calendar
Security
- Passcode lock for data protection (Touch ID supported)
- OpenPGP for email encryption and decryption
- Reports of suspicious emails sent to the system administrator for spam learning enhancement
Settings
- Custom swipe options: delete, archive, mark as Spam/Not Spam, mark as read/unread, apply labels, move to a certain mailbox
- Custom preview lines based on user preferences
- Font size settings: large, medium, small
- Push notifications when there is an email received in the user-defined mailboxes
- Mobile signature settings for sender information display
- Multiple templates for a quick reply
- Auto remote images loading
- Email content prefetching on Wi-Fi only
- Integration with Synology Calendar or other calendar applications
- Mailbox management: create, edit, and delete mailbox
- Label management: create, edit, and delete labels
- Cache storage limit for images and attachments

Notes:

Please note that the figures marked in asterisks are derived from the Synology lab by using high-performance client computers with optimized network settings, and could vary in different environments.