Open Source Apple iPhone Email Apps

Thunderbird iOS is the official iPhone and iPad email client offering from the Thunderbird project, bringing the capabilities of a feature-rich, open-source email experience to iOS devices with native UI and Apple platform integrations. The app gives users a powerful tool for managing multiple email accounts, including IMAP and POP3 configurations, and supports modern authentication flows like OAuth for popular providers. Designed with mobile usability in mind, it includes familiar gestures, thread views, swipe actions, attachment previews, and integrated search so users can stay productive on the go. It also handles common email needs like organizing with folders, setting flags, and filtering messages, while respecting platform norms for notifications, background fetch, and data usage. By maintaining a connection to the desktop Thunderbird project’s ethos, the iOS client places emphasis on transparency, extensibility, and user control.

Tutanota is an open source email client focused on security and privacy. It is built with end-to-end encryption and 2FA, so you can be assured of utmost email security. Tutanota is always encrypted, so whether you’re using their secure webmail client, mobile apps or desktop clients, you can be sure to communicate securely.

Proton Mail for iOS is the official iPhone and iPad client that brings Proton’s secure, end-to-end encrypted email service to Apple’s mobile ecosystem, combining strong privacy protections with native performance and gestures. The app allows users to sign in to one or multiple Proton Mail accounts, read and compose encrypted messages, schedule emails, protect emails with passwords, set expiration timers, and organize mail with labels and folders inside a smooth, intuitive iOS interface. It makes use of Apple’s networking APIs and encryption frameworks to deliver seamless management of encrypted communications while respecting platform conventions like touch navigation, Apple notifications, and background refresh. All sensitive operations — including key handling and encryption — occur locally on the user’s device, ensuring that plaintext messages and secret keys are never exposed to Proton’s servers or third parties.

Extensible web mail client, allowing UI to be redefined according target format (modern Web browser, mobile device ...).

Sometimes you just want to send a simple HTML email with a simple design and clear call to action. This is it. This is a really simple email template. Its sole purpose is to get the recipient to click the button with no distractions. Save yourself the pain of coding HTML email and download email templates. There are over 30+ major email clients using different rendering engines and various email providers like Outlook, Gmail, Apple, Yahoo Mail. Email requires special development skills. It is important to consider the experience for iOS and Android users if you really want to get your return on investment. A broken mobile experience can break your campaign. You have a lot to do. You have websites to design, code to test, products to ship, campaigns to send. That's why these templates were created, to save you time. These HTML email templates have been tried and tested across all major email clients.

MailTrackerBlocker is a macOS Mail plugin that prevents email tracking pixels from collecting user data. It enhances privacy by blocking hidden tracking mechanisms used by marketing emails.

ObjectivePGP is an open-source library for OpenPGP encryption, decryption, signing, and verification in Objective-C and Swift. It enables developers to add PGP-based security to iOS and macOS apps.

Thexyz Cloud Drive application allows you to synchronize files on your desktop with your cloud storage space. This gives you instant access to the most recent versions of important files from anywhere and from any device. Need to edit that important document, but don’t have access to your desktop computer? With the editors included in Cloud Drive, you can create, access, and edit documents and spreadsheets right from your browser.

This Software converts Kolab V2. Adress-Books to a readable and searchable Format for the iPhone and other IMAP-Capable Devices.

mail2prowl is used to operate the free service http://mail2prowl.de This script receives mails via POP3, reads a special formed recpeint adress and sends the mail to the Prowl webservice. Prowl is a push enabled iPhone Application with a nice API.

A Free form-data to Email platform. Anyone can fetch form data to their mail box without having to write server side code!