Quillbox

Android email client: downloads IMAP/POP3 mail, composes new messages with a standard formatting toolbar, and routes incoming mail into folders (e.g. Spam) via user-defined rules.

Email client for Android, desktop, web and iOS: downloads IMAP/POP3 mail, composes with a formatting toolbar, and keeps junk out of the Inbox with open DNS blocklists, an offline brand-impersonation detector, a learning classifier and user rules. The web client is laid out like Microsoft 365 Outlook.

Features Account setup — host, port, username, password, protocol (IMAP/POP3) and an SSL·TLS / STARTTLS / None security selector, with an optional Verify & Save that connects before persisting. Separate SMTP host/port/security for sending. Mail download — a repository layer connects, fetches message headers + bodies, and stores them in Room. Folder list → message list → message detail screens, all with pull-to-refresh. Compose — a rich-text editor with a formatting toolbar (bold, italic, underline, bulleted list, numbered list, attach, send). Supports To/Cc/Bcc, subject and file attachments (via the Storage Access Framework). Sends over SMTP using the account credentials and files a copy into Sent. Rules engine — a user-manageable rule list. Each rule combines criteria (sender contains / subject contains / body keyword) with AND/OR logic and an action (move to folder e.g. Spam, mark read, or delete). Rules evaluate against incoming mail on every fetch. A Default Spam Filter rule is seeded on first launch. Rules are persisted in Room.