Setting Up Business Email with Synology MailPlus

In today’s enterprise environment, maintaining control over business communications is essential for data sovereignty, compliance, and cybersecurity resilience. Synology MailPlus provides a robust, on-premises email solution that transforms a compatible Synology NAS into a full-featured mail server. It supports SMTP, IMAP, and POP3 protocols while offering advanced security, AI-powered productivity tools, and seamless integration with Synology’s storage and backup ecosystem.

For IT managers and business owners, MailPlus delivers cost-effective email hosting without monthly SaaS fees, full data ownership, and tight integration with scalable storage solutions. This guide outlines the step-by-step process for setting up professional business email while emphasizing best practices for security and integration with enterprise data protection strategies.

Why Choose Synology MailPlus for Business Email?

Synology MailPlus Server offers several enterprise advantages:

Data Ownership and Privacy: All emails and configurations remain on your NAS, reducing exposure to third-party providers.
High Availability: Optional clustering ensures uninterrupted service during hardware maintenance or failures.
Advanced Security: Built-in anti-spam, SPF/DKIM/DMARC support, S/MIME encryption, and detailed audit logs.
Productivity Features: AI tools for email summarization, smart replies, and drafting; shared mailboxes, mail merge, tracking, and integration with Synology Calendar, Contacts, and Chat.
Scalability: Supports multiple domains, user policies, quotas, and licensing (5 free licenses included; additional licenses available).
Migration Ease: Built-in tools to migrate from Microsoft Exchange, Google Workspace, Gmail, or other IMAP servers.

When paired with Synology Expansion Units and robust backup solutions, MailPlus becomes a secure cornerstone of enterprise IT infrastructure.

Before starting:

A compatible Synology NAS running DSM 7.1 or later (check official applied models; x86-64 recommended for AI features).
At least 8 GB RAM for optimal performance and AI capabilities.
A registered domain name with access to DNS records (MX, SPF, DKIM, DMARC).
Static public IP or reliable DDNS configuration with proper port forwarding (ports 25, 465, 587 for SMTP; 143, 993 for IMAP; 110, 995 for POP3).
Firewall rules configured on your router and Synology NAS.
Enterprise-grade storage volume (consider SSD caching or tiering for better performance).

Step-by-Step Setup of Synology MailPlus

Step 1: Install MailPlus Server and MailPlus

Log into the DSM web interface.
Open Package Center, search for MailPlus Server, and install it.
Install the MailPlus client package for the webmail interface.

Step 2: Launch the Setup Wizard

Launch MailPlus Server.
In the wizard, select Create a new mail system (or choose migration options if transferring from an existing server).
Choose account types (local DSM users, LDAP, or domain users) that can access email services.
Configure basic settings: default email address format, storage location (dedicated shared folder recommended), and initial domain.

Step 3: Configure DNS Records

Proper DNS setup is critical for deliverability:

Add an MX record pointing to your NAS (or DDNS hostname).
Create SPF, DKIM, and DMARC records to prevent spoofing and improve inbox placement.
Set up reverse DNS (PTR) if possible for outgoing mail reputation.

Refer to Synology’s official DNS configuration guide for exact record formats.

Step 4: Set Up Domains and User Accounts

In MailPlus Server, go to Domain and add your business domain(s).
Customize policies, quotas, aliases, disclaimers, and auto-BCC rules per domain.
Enable mail services for users via Service > SMTP/IMAP/POP3.
Assign email addresses to DSM users or create dedicated accounts.

Step 5: Configure Security Settings

Enable anti-spam with auto-learning and Rspamd.
Activate antivirus scanning (ClamAV by default; add Bitdefender license for enhanced protection).
Configure authentication (reject unauthenticated mail, enable TLS/SSL).
Set up content protection, S/MIME, and audit logging.
Whitelist trusted senders and domains as needed.

Step 6: Enable Additional Features and Integration

Activate AI tools (requires external AI provider keys) for smart email handling.
Integrate with Synology Calendar, Contacts, and Chat for unified collaboration.
Set up mail migration tasks if importing existing emails.
Configure high-availability clustering for mission-critical setups (two NAS devices).

Step 7: Test and Go Live

Send test emails internally and externally.
Verify receiving, spam filtering, and mobile access (via IMAP or web client).
Monitor mail queue, logs, and server status in the management console.

Enterprise Best Practices for Security and Data Protection

Use dedicated storage volumes with snapshot protection and replication for the MailPlus shared folder.
Implement regular backups using Synology’s Hyper Backup or Active Backup for Business, combined with off-site or cloud replication.
Apply least-privilege policies and two-factor authentication for admin access.
Monitor system resources and scale storage with Synology Expansion Units as email volume grows.
Schedule security updates and maintain strong firewall rules to defend against threats.

Combining MailPlus with comprehensive data protection strategies ensures ransomware resilience and business continuity.

Common Challenges and Troubleshooting

Email Deliverability Issues: Double-check DNS records and avoid residential IP blacklisting (consider SMTP relay services if needed).
Performance: Enable SSD cache or use high-performance volumes for large user bases.
License Management: Add additional licenses directly in MailPlus Server as user count grows.

For complex deployments involving multiple domains, high availability, or integration with existing IT infrastructure, professional Synology consulting is recommended to optimize configuration and security.

About Epis Technology

Epis Technology provides enterprise IT infrastructure, cloud backup, data protection, and Synology consulting services. The company specializes in Microsoft 365 and Google Workspace backup solutions, large storage and scalable data management systems, fully managed PC backups, Synology support, deployment, and consulting, as well as business continuity, cybersecurity resilience, and IT performance optimization. Their experts help businesses deploy secure on-premises solutions like Synology MailPlus alongside robust storage and backup strategies tailored to enterprise needs.

Setting Up Business Email with Synology MailPlus