Email as you know it
Folders with unread counts, a list grouped by today/yesterday/this week, a reading pane, replies with the classic header block – and attachments that actually show up.
Neruna Desktop · Beta 0.1
Mail, calendar, contacts.Free at last.
Everything in one app that feels like the office software you know – just without licence fees and without your data ending up in someone else's cloud. For IMAP, CalDAV and CardDAV, for example with SOGo or Nextcloud.
Free.
Forever.
Bye bye,
licence fees!
Forever.
licence fees!
Features
Feels familiar. Belongs to you.
Everything you know from everyday office work – plus a few things many free mail programs never learned. Not webmail in a window, but a real desktop client: fast and offline-capable.
Write with style
Font (previewed in the font itself!), size, colours, lists, links, images. In the reading pane or in its own window.
S/MIME built in
Signs automatically when you have a certificate – and encrypts automatically as soon as all recipients have one. No plug-ins, no tinkering.
A calendar that thinks along
Time grid in 15/30/60 minutes, 7 days or Mon–Fri, month overview, your own colours. And: reload subscribed SOGo calendars at any time.
Contacts & mailing lists
Colour-coded address books, contact photos and groups – where you choose for each person which address the list uses.
Signatures per account
One for new messages, one for replies. With formatting and logo, switchable with one click while writing.
Works offline
Mail, events and contacts are kept locally in a database. Reading and searching work even on a train without signal.
Privacy first
Remote images in emails are blocked until you allow them. No tracking, no ads, no data in someone else's cloud.
Your look
Light, dark or like your system, colour scheme blue, red or green. Sort your accounts; folders stay expanded or collapsed the way you left them.
Compose
Formatting without swearing.
The biggest annoyance of many free mail programs? Fixed. The editor does what you expect – and shows every font in the font itself.
- Font, size, colour – bold, italic, underline, strikethrough, highlight
- Replies like you're used to – with header block, the original keeps its formatting
- Pop out – move a draft into its own window with one click
- Insert images – embedded automatically
Calendar
Your week, at a glance.
A time grid as you know it, the month overview on the left, colours to your taste. And calendars subscribed in SOGo can be reloaded at any time – not only during setup.
- List or time grid – divided into 60, 30 or 15 minutes
- 7 days or Mon–Fri – switch at the top right
- Manage calendars – new subscriptions are offered as “new”
- Internet calendars via ICS/webcal
Contacts
Mailing lists that use the right address.
Lea has a work and a private address? Use the private one for the barbecue list and the work one for the project team. Per group, per person.
- Colour-coded address books – see at once where a contact comes from
- Groups & lists – also with addresses that aren't contacts
- Contact photos – faces instead of initials
- Compatible – groups in the common CardDAV format, e.g. for SOGo
Your data
Your groupware. Your servers. Your rules.
We host nothing – on purpose. Neruna connects directly to your mail server. Mail, events and contacts stay where they belong: with you or your provider – not with us.
Neruna Cloud, too, will only store configuration: server settings, signature templates, shared calendar links. And your configuration vault is encrypted with your password before it ever reaches our server.
Neruna Desktopon your computer · local offline copy
⇅ Mail, events, contacts – direct, encrypted (TLS)
Your serverSOGo, Nextcloud, Dovecot, Radicale … or your host
⇣ configuration only – optional, later
Neruna Cloud / ControlAutoconfig, signatures, vault – no user data
Screenshots
Real pictures. Real app.
No mock-ups – this is what Neruna Desktop looks like today. Click to enlarge.
The screenshots show the German interface – English, French and Italian will follow.
Products
One family, three sizes.
The client is and stays free. For companies, central management comes on top – as a cloud service or on your own server.
Neruna Desktop
neruna.org
The mail, calendar and contacts client for everyone. Open source, free, no account with us.
- IMAP, SMTP, CalDAV, CardDAV, ICS
- S/MIME, HTML editor, signatures
- Works offline, light & dark
Neruna Cloud
neruna.cloud
Management for teams as a service. Your mail stays on your server – the cloud only knows the settings.
- Set up accounts automatically (autoconfig)
- Central signatures & templates
- Shared calendars, configuration vault
Neruna Control
self-hosted
Everything from Neruna Cloud – on your own server. For everyone who won't even hand over their settings.
- PHP / Laravel / MariaDB, Docker
- Multi-tenant
- No dependency on us
Pricing
Free means free.
No trial period, no ads, no pro version that holds features back from you.
Desktop
For you, your family, your club.
CHF 0 forever
- All client features
- As many accounts as you like
- S/MIME, signatures, groups
- Open Source
Cloud
For teams and SMEs that want central management.
Price to follow
- Everything in Desktop
- Autoconfig for all users
- Central signatures & templates
- Configuration vault (zero knowledge)
- Shared calendars
Control
For IT service providers and organisations with their own data centre.
Price to follow
- Everything in Cloud
- On your own server, via Docker
- Multiple tenants
- Full data sovereignty
All prices in CHF. Cloud and Control are in development – get in touch and you'll be the first to know.
Releases
What's in it. What's next.
0.1 Beta Current
October 2026 · Windows x64
- Email via IMAP/SMTP with offline cache
- HTML editor, signatures, pop-out
- S/MIME: automatic signing & encryption
- Calendar: list, time grid, month overview, subscriptions
- Contacts: address books, groups, photos
- Design: light/dark, three colour schemes
Next up Planned
Neruna Cloud & Control
- One-click account setup
- Central signatures and templates
- Configuration vault: restore everything
- Signed Windows installer
Later Ideas
Roadmap
- Linux and macOS packages
- Exchange (EWS) as another provider
- App in English, French, Italian
- Global contacts as an add-on
Beta test
Become a beta tester.
Neruna Desktop 0.1 is already running – for now we hand out the beta personally to testers. Drop us a line about the mail server you use, and you'll get the download as soon as a spot opens up.
- System
- Windows 10 or 11, 64-bit
- Delivery
- ZIP, approx. 50 MB – unzip and run, no installation
- Formatting
- WebView2 (preinstalled on Windows 11)
- Server
- IMAP/SMTP, CalDAV, CardDAV – e.g. SOGo, Nextcloud
- Note
- The beta isn't signed yet: Windows SmartScreen will ask – “More info” → “Run anyway”. The interface is in German for now.
FAQ
Good questions.
Is Neruna Desktop really free?
Yes. The client is open source and costs nothing – not even for companies. We'll make money later with Neruna Cloud and Control, the central management for teams.
Which servers does Neruna work with?
With anything that speaks IMAP/SMTP for mail and CalDAV/CardDAV for calendars and contacts – for example SOGo, Nextcloud, Dovecot, Radicale or most hosting providers. Internet calendars can also be subscribed via ICS/webcal.
What about Exchange servers?
Not directly yet. The architecture is prepared for it; an Exchange (EWS) provider is on the roadmap. Until then Exchange works for mail, as long as IMAP is enabled.
Where is my data?
On your mail server – and as an offline copy on your computer. We don't host any data. Passwords are never stored in plain text.
Can I see my subscribed SOGo calendars?
Yes – and not only during setup: under “Manage calendars”, Neruna asks the server again at any time and shows newly subscribed calendars as “new”.
What language is the app in?
The beta is in German. English, French and Italian are planned – the app has been built for it from the start.
Is Neruna available for Linux or macOS?
Neruna is built cross-platform from the ground up (.NET and Avalonia). The beta comes for Windows first; Linux and macOS packages will follow.
Why does Windows warn me on first start?
The beta isn't signed with a code-signing certificate yet, so Windows SmartScreen asks first – continue with “More info” → “Run anyway”. A signed installer will follow.