CrowdInbox

A free email app by ServerCrowd

Your email stays on your device.

CrowdInbox is an email app that retrieves your email directly from your mail server, stores it on your device and sorts it on arrival. It states the reason for every classification.

Download the app What happens to your data
  • No account required
  • No advertising
  • Optional relay in Germany

CrowdInbox, taken apart into its layers

Overview

What is CrowdInbox?

CrowdInbox is an email app made by ServerCrowd GmbH, a company based in Neustadt am Rübenberge, Germany. The app is free and requires no account. It connects directly to your own mail server over IMAP and SMTP and stores your email on your device.

€0
The email app is free on every platform.
DE
The optional relay runs on servers in Germany.
0
You need no account with us to read and write email.
3
Email is sorted into three categories, and the reason is shown.

01Sidebar

Works with your existing email accounts

  • Gmail
  • Outlook
  • iCloud
  • GMX
  • WEB.DE
  • T-Online
  • Posteo
  • mailbox.org
  • Fastmail
  • IONOS
  • Yahoo
  • any IMAP server

How to add Gmail, Outlook and iCloud

02Message list

Three categories, each with a stated reason

The app sorts your email on arrival into People, Notifications and Newsletters. You can add any number of mailboxes, and the list shows the email from all of them together.

03Reading pane

Your email is stored on your device

The app retrieves your email from your mail provider and stores it on your device. Neither the iPhone app nor the desktop app contains advertising or tracking libraries.

04Reason

Why is this here?

For every message, CrowdInbox shows the reason for its classification. The reason may be, for example, that you have written to the sender before, that the message is a reply to your email, or that it was sent through a mailing list.

05Relay

The relay stands beside the app and is switched off

The relay of CrowdInbox by ServerCrowd is an optional service on servers in Germany. It is used only for three features that you switch on yourself: instant notifications on the iPhone, sending scheduled email while all your devices are switched off, and the account that carries CrowdInbox Plus across your devices.

What the relay receives

Platforms

All your email accounts in one inbox, on your phone and your computer

If you have several email accounts, CrowdInbox shows the email from all of them in one unified inbox, and you can switch to a single account at any time.

All versions are built on the same core, so a rule you create on your phone works in exactly the same way on your computer. The desktop app is a complete email client for Windows, macOS and Linux, and it is free as well.

  • iPhone (in TestFlight)
  • Windows, macOS and Linux (preview)
  • Android (planned)

Until its release in the App Store, the iPhone app is available through TestFlight, and the test is open to everyone. A preview of the desktop app is available for Windows, macOS and Linux. An Android version is planned.

Features

What CrowdInbox does with your email

Feature 1 of 9

Automatic sorting with reasons

CrowdInbox sorts incoming email into People, Notifications and Newsletters and shows the reason for each decision. If you move a message to another category, the app creates a rule for that sender, and the rule applies on all your devices.

Sara Okafor

Notes from the workshop

People

Why is this here?

  • It is addressed to you directly
  • The sender name looks like a person
  • Nothing suggests it was sent automatically
  • Your rule for this sender
Move to

For every message, CrowdInbox shows the reason for its classification.

Feature 2 of 9

Snooze

A snoozed message is moved out of the inbox and reappears at the time you choose. CrowdInbox uses a folder in your own mailbox for this, so all your devices show the same state.

Lena Hartmann · Tickets for Saturday
Mia Wolf · Offer for the summer
Tom Schäfer · Invoice 2026-0412

Snoozed until Monday, 08:00

Feature 3 of 9

Search as you type

CrowdInbox searches the email stored on your device and shows results as you type. If you need more than is stored on the device, you can extend the search to the mail server.

  • Priya Raman · Quote
  • Jonas Becker · Sunday
  • GitLab · Pipeline
  • Lena Hartmann · Tickets

Feature 4 of 9

Send later

You choose when an email is sent. At the chosen time, the device on which you scheduled the email sends it through your own mail server. If CrowdInbox is not running on that device at that time, the email is sent as soon as the app runs there again.

To: Lena Hartmann

Tomorrow · 07:00 Sent

Addition to feature 4 Relay

Send Later Without the App

When this feature is switched on, the app hands every scheduled email to the relay of CrowdInbox by ServerCrowd. The relay stores it in encrypted form, sends it through your own mail server at the chosen time, even if all of your devices are switched off, and deletes it afterwards. The feature is not available for mailboxes with Microsoft sign-in.

Your devices Switched off
Relay In Germany
Your mail server Sends the email
  1. Stored in encrypted form
  2. Sent at the chosen time
  3. Deleted after sending

More features

What else the app does

Feature 5 of 9

Remind me if nobody replies

If nobody replies to an email you sent, CrowdInbox moves the conversation back to the top of the inbox at the time you set. The reminder is cancelled automatically as soon as a reply arrives.

No reply for 3 days · back on top

You: Can we move the call to Thursday?
Lena Hartmann · Tickets for Saturday
Tom Schäfer · Invoice 2026-0412

Feature 6 of 9

Protection against tracking

Remote images remain blocked until you load them once or trust their source. This prevents tracking pixels from reporting that you opened an email.

Images blocked

Feature 7 of 9

Unsubscribe from newsletters

CrowdInbox shows an Unsubscribe button for newsletters. The app uses the method the newsletter itself specifies and tells you beforehand what will happen.

Rust Weekly

This week in Rust #612

Contains an unsubscribe link

Feature 8 of 9

Light and dark

The app has a light and a dark appearance and can follow your system setting. You choose separately how the content of your email is displayed.

Inbox

Lena HartmannTom SchäferSara Okafor

Inbox

Lena HartmannTom SchäferSara Okafor

Feature 9 of 9

German and English

The entire app is available in German and English. This includes date formats and the reasons the app gives for sorting your email.

  • Inbox Posteingang
  • Snoozed Erinnerungen
  • Send later Später senden
  • Pinned Angeheftet

Privacy

What CrowdInbox by ServerCrowd can and cannot see

Your email is transferred directly between your devices and your own mail server. The relay is involved only in three features, and only once you switch them on. Select a feature to see what it changes.

Relay: Switched off

Without the relay, your email stays between your devices and your mail server

The connection to your mail server is encrypted. ServerCrowd receives none of the following data:

  • Your messages, their attachments and their senders
  • Your password, which is kept in the credential store of the operating system
  • Your search queries and the results of the sorting
  • Which messages you read, pin, archive or delete
Between your devices and your mail server
Your email, direct and encrypted

Relay: Switched on

Instant notifications on the iPhone Relay

The relay signs in to your mailbox and monitors it for new email. For this purpose it stores the password in encrypted form and deletes it as soon as you switch the feature off.

  • The push notification itself contains no sender, no subject and no text.
  • The relay reads only the numbers of the messages in the inbox, not their content.
  • The feature is not yet available for mailboxes with Microsoft sign-in.
Between your devices and the relay
A notification without content
Between the relay and your mail server
Checks for new email

Relay: Switched on

Send Later Without the App Relay

The relay stores the scheduled email and the password needed to send it in encrypted form and sends the email through your own mail server at the chosen time.

  • After sending, the relay deletes both the email and the password.
  • If you change or delete the scheduled email beforehand, the relay no longer sends it.
  • The feature is not available for mailboxes with Microsoft sign-in.
Between your devices and the relay
The scheduled email, encrypted
Between the relay and your mail server
Sends at the chosen time

Relay: Switched on

The CrowdInbox account Relay

The account consists of your email address and a code that we send to that address. Our mail server logs the address when it sends the code.

  • The relay stores only a fingerprint of the address.
  • The account is optional and has no password.
  • You need it only if you buy Plus on the website or use Plus bought on the iPhone on other devices.
Between your devices and the relay
Your address and the code

Features marked “Relay” run through the relay of CrowdInbox by ServerCrowd, a service on servers in Germany. You switch them on yourself. Everything else happens directly between your device and your mail server.

Read the privacy policy

Pricing

The app is free. CrowdInbox Plus funds the operation of the servers.

Reading, sorting, searching and sending email are free on every platform and require no account. CrowdInbox Plus covers what goes beyond the email app: the relay, which keeps working while your devices are switched off, and the summaries on the iPhone.

CrowdInbox

Free no time limit

  • For iPhone, Windows, macOS and Linux
  • Any number of email accounts in one unified inbox
  • Sorting with reasons, search and snooze
  • Unsubscribing from newsletters and protection against tracking
  • Send later from your own device
  • No account required
Download the app

CrowdInbox Plus Planned

€19.99 a year

Everything in the free app, plus:

  • Instant notifications on the iPhone when new email arrives Relay
  • Sending scheduled email while all your devices are switched off Relay
  • Summaries and suggested replies on iPhones with Apple Intelligence, generated on the device
  • Plus on all your devices with one purchase, through the optional CrowdInbox account Relay
More about Plus

Plus is not on sale yet. Until it is, instant notifications and “Send Later Without the App” work without Plus.

On the iPhone, you can also pay monthly, at €1.99 a month; the annual price is 16% lower than twelve monthly payments. The supporter price on the iPhone is €39.99 a year. It includes the same features, and the higher amount helps to fund the service.

For mailboxes with Microsoft sign-in, instant notifications are not yet available, and scheduled email continues to be sent from your device.

Features marked “Relay” run through the relay of CrowdInbox by ServerCrowd, a service on servers in Germany. You switch them on yourself. Everything else happens directly between your device and your mail server.

Use CrowdInbox free of charge

CrowdInbox is free on iPhone, Windows, macOS and Linux.

Download CrowdInbox