SynoMail

1.0.2

SynoMail is a native macOS client for Synology MailPlus Server: your NAS mail in a real Mac app, no browser needed.

SynoMail connects straight to MailPlus Server on your Synology NAS through the DSM API, like the official mobile app, and shows your mail in a three-column macOS interface.

Independent app, not affiliated with Synology Inc. No account, no cloud: SynoMail only talks to your NAS.

Features

Mail

Folders and conversations

Inbox, system and custom folders, conversation grouping, server-side search, unread count in the Dock.

Reading

Safe HTML

Messages render with JavaScript off; links open in your browser; attachments save in one click.

Compose

Reply and send

New message, reply, reply all, forward, CC and BCC, drag-and-drop attachments, drafts.

Sign-in

YubiKey and Secure SignIn

Password and 2FA code, or the DSM sign-in page with a security key, passkey or Secure SignIn approval.

Organize

Fast triage

Read/unread, flag, drag to move, archive, spam, labels, keyboard shortcuts.

Privacy

Password in the Keychain

The password and 2FA device token are stored in the macOS Keychain.

What’s new

Version 1.0.2, 30 October 2026

Dates follow the language chosen in the app.
The standard macOS menus (File, Edit, Window, Help) are translated; a language change applies to them on the next launch.
Long addresses no longer overflow the message header.

Installation

1
Download and drag
Open the DMG and drag SynoMail into Applications.
2
Confirm the first launch
SynoMail is signed by its author but not notarized by Apple: System Settings → Privacy & Security → "Open Anyway".
3
Sign in to the NAS
Enter the NAS address (usually https://<nas>:5001) and sign in with your DSM account.

Questions and answers

What does the NAS need?

Synology MailPlus Server with the MailPlus client enabled for your user.

Which Macs?

macOS 14 or later, Apple Silicon and Intel.

Self-signed certificate?

Supported: the "Self-signed certificate" option trusts your NAS certificate only.

Linked to Synology?

No. SynoMail is an independent app that uses your NAS API.

How do I check the downloaded file?

In Terminal, run the command below and compare the result with the SHA-256 fingerprint on the right. If a single character differs, do not open the file and write to us.

shasum -a 256 ~/Downloads/SynoMail-1.0.2-universal.dmg

Version: 1.0.2
Developer: IBCSC, Charleroi
Interface languages: Français, Nederlands, Deutsch, English, Русский, Español
Compatibility: macOS 14 or later
Architecture: ARM, x86 (64-bit)
Licence: Free, no ads
Signature: Author’s certificate (not notarized by Apple)
SHA-256 fingerprint: 83c0a092c0a1…2bc633