Silver

Modern Collaborative Email Platform

Silver aims to build a new kind of email and communication system that can work at a government scale. The goal is to make email faster, smarter, and easier to manage while keeping it secure and reliable. The platform will evolve in two stages: Version 1.0 delivers reliable, standards-compliant email, while Version 2.0 reimagines communication with modern collaboration at its core.

• Why Silver? • Key Features • Getting Started • Open Source Components • Contributing • License •

Why Silver?

Silver is designed to be secure, reliable, and easy to manage. It runs entirely on your own hardware, giving you full control over your data and ensuring privacy. The system is lightweight and efficient, performing well even on minimal hardware, which makes it easy to deploy in a variety of environments. Each user has a single, unified identity, so an email address and user identity are seamlessly connected. You can bring your own identity provider or use Thunder to organize your users and map your organization hierarchically.

External firewalls are not required to filter emails, and attachments are stored separately in blob storage to save space and improve overall system performance. Silver also includes built-in observability, allowing administrators to monitor activity, detect issues early, and maintain smooth operation.

Key Features

Silver offers powerful capabilities that set it apart from traditional email solutions:

Feature	Status
Unmatched Cost Efficiency – Reduce enterprise email costs to near-zero infrastructure expense.	Completed
Lightweight Infrastructure – Run on minimal hardware without compromising performance	Completed
Complete Data Ownership – Full control over storage, access, and security	Completed
Built-In Security Protection – Enterprise-grade spam filtering and malware scanning	Completed
Professional Role-Based Identity – Authoritative organizational email addresses	In Progress
Smart Attachment Storage – Separate object storage for improved performance	In Progress
Identity Provider Integration – Seamless integration with existing IdP systems	Planned
Disaster-Proof Backups – Configurable backup strategies for data protection	Planned
Effortless Group Emailing – Organize users into groups for simplified communication	Planned
Email Workflow Automation – Route emails through predefined workflows with tracking	Planned
High-Performance Email Client – Native IMAP and JMAP support for faster sync	Planned
Email Expiration Control – Set expiration dates and retention policies	Planned

View Complete Feature List →

Getting Started

Prerequisites

• A dedicated Linux server with a static public IP address. You also require root access and port access control.
• Domain with DNS control

Minimum hardware requirements

• 4GB of memory

Software

• Ensure you have Git and Docker Engine installed

DNS setup

You own example.com and want to send an email as [email protected].

You will need to add a few records to your DNS control panel.

Note

Replace example.com and 12.34.56.78 in the below example with your domain and ip address.

DNS Record	Name	Value
A	mail	12.34.56.78
A	example.com	12.34.56.78
MX	example.com	mail.example.com
TXT	example.com	"v=spf1 ip4:12.34.56.78 ~all"
TXT	_dmarc	"v=DMARC1; p=quarantine; rua=mailto:[email protected]"
PTR	12.34.56.78	mail.example.com

Tip

PTR records are usually set through your hosting provider.

Server Setup

• Use the below command to clone the Silver Repo and navigate to the silver folder.

git clone https://github.com/LSFLK/silver.git
cd silver

Configuration

• Open silver.yaml with a text editor.

• Enter your domain name.

• Run bash ../scripts/setup/setup.sh to set up the configs.

• Run bash ../scripts/service/start-silver.sh to start the mail server.

• Replace the dkim record below with the output you get after running the setup.sh script

DNS Record	Name	Value
TXT	mail._domainkey	"v=DKIM1; h=sha256; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDYZd3CAas0+81zf13cvtO6o0+rlGx8ZobYQXRR9W8qcJOeO1SiQGx8F4/DjZE1ggujOaY1bkt8OnUg7vG7/bk5PNe05EHJrg344krodqCJrVI74ZzEB77Z1As395KX6/XqbQxBepQ8D5+RpGFOHitI443G/ZWgZ6BRyaaE6t3u0QIDAQAB"

Important

Ensure that your dkim value is correctly formatted.

Adding users

• To add more users to your email server, open up users.yaml, and add their usernames and run the following command.

# silver/services
bash ../scripts/user/add_user.sh

• Follow the prompts to add a new user.

Testing your setup

• Now that you have a working email server, you can test your configuration using the following links/scripts.

  • mxtoolbox
    • MxToolbox is a powerful online service that provides a suite of free diagnostic and lookup tools for troubleshooting email delivery, DNS, and network issues.
  • mail-tester
    • Mail-Tester is a free online tool that analyzes the "spamminess" of your email and server configuration, providing a score out of 10 to help improve your email deliverability.

• You can also set up a Mail User Agent (MUA) like Thunderbird to send and receive emails. Follow the instructions in Mail User Agent Setup.

Open Source Components

Email Flow in Silver

Figure 1: Outbound Email Flow

Figure 2: Inbound Email Flow

Silver is built using open-source software.

• Postfix - handles sending and receiving email.
• Raven - handles SASL authentication, LMTP, and IMAP server for email retrieval.
• Thunder - Identity provider and user manager
• Rspamd - spam filtering system.
• ClamAV - virus scanning system.
• Certbot - Client software that talks to Let’s Encrypt to generate certificates.

Contributing

Thank you for wanting to contribute to our project. Please see CONTRIBUTING.md for more details.

License

Distributed under the Apache 2.0 License. See LICENSE for more information.