Most mail apps answer "what did I receive?" Corres answers "what needs me?" It opens on Needs You, with the replies you're owed one row above, and every message is still one swipe along in Mail. Nothing is sorted out of reach.
Built by Anwar Creative Studio, alongside Artha. Status: in beta on TestFlight for iPhone and iPad (Build 17) and for Mac (Build 18), one purchase across all three. Website: corres.app.
What it does
One home, opening on what needs you
- Needs You: conversations that ask something of you, each with a one-line reason, grouped into Due soon and When you can. Press and hold any conversation to move it if Corres got it wrong, and it learns.
- Waiting: conversations you replied to or moved there, with how long you've been waiting and a nudge when it's time to follow up.
- Mail: Primary, Everything, Unread, Promotions, Social and Updates, sorted by Corres's own rules on top of each provider's, across every account or one at a time.
- New senders: a first email from someone new waits for Allow or Block. Allow or block a whole company at once.
- Search that answers: search every account at once, archived mail included, with
from:, to:, has:attachment, is:unread and is:flagged, or type a question ("When is my next flight?") and get the answer from your own mail above the results. Results keep going past the first 50 from each account as you scroll, and include what the provider's own search found deep inside an email.
- Home Screen Search: your newest 5,000 conversations are indexed on the device for Spotlight, and a result opens straight to the conversation. Settings → Reading → Show in Search turns it off.
Every account
- Gmail and Google Workspace, Outlook.com and Microsoft 365, iCloud Mail, and Yahoo, AOL, Fastmail, Zoho or a work server with just an address and password.
- Postwright, our own IMAP and SMTP engine (
Packages/Postwright), for iCloud and other accounts.
- New Outlook and iCloud mail notifies in seconds, even with Corres closed.
- The whole mailbox, not just the newest page: after the first sync, the past year of mail (up to 5,000 conversations per mailbox) comes onto the device in the background, metadata only, so Search finds it at once.
- What you do elsewhere shows up here: every account is checked every 20 seconds while Corres is open, Outlook pushes changes and deletions as well as new mail, and mail moved or deleted in another app leaves Corres too, confirmed with the server before anything is removed.
- Settings shows when each account last synced, and says plainly when a sign-in has lapsed or a service is refusing.
- Accounts follow you: add one on your iPhone and it's ready on your iPad and Mac, through iCloud Keychain. Remove it and it's gone from all of them.
A complete mail app
- Whole conversations: earlier messages appear as compact rows above the latest one, open in place, and long threads fold in the middle.
- Read, reply, reply all, forward and compose, with attachments, Send Later, Undo Send, follow-up reminders, signatures, send-as addresses, and bold, lists and links.
- Invitations: the time in your own time zone (Outlook's Windows zone names included), the place, a Join button for Meet, Zoom or Teams, the repeat rule, and whether you're free. Accept, Maybe or Decline sends the organizer a standard calendar reply; Add to Calendar puts it on yours. An updated invitation asks again, and a canceled one says so and can take the event off your calendar.
- Undo after Archive or Trash; Archive and Mark as Read from a notification; a reply straight from a notification.
- Works offline: archive, delete, move, read and flag wait on the device and reach the server in order once it can.
- Your choices (Needs You, Waiting and Handled, snoozes, pins, allowed and blocked senders, VIPs and settings) sync between your devices through iCloud. Mail itself never does.
- Apple Mail's keyboard shortcuts on iPad and hardware keyboards, and a three-column layout on iPad.
- Needs You and Waiting widgets, Siri and Shortcuts ("What needs me in Corres"), and a Morning Brief notification.
- Snooze by typing a time ("in 3 days at 9am") or picking a preset; Pin; four custom swipes.
On the Mac
- A native Mac app (
Mac/, the CorresMac target), not an iPad app stretched to fit: three columns, a fast message list, keyboard shortcuts for every action, menus, and conversations in their own windows.
- The same engine, rules and accounts as the iPhone, with rich text compose, snooze, drafts, server search and the invitation card.
- One purchase across iPhone, iPad and Mac (the same bundle ID).
Shaped around you
- Settings → Customize: lists, swipes, and up to five actions under an email from 18; the rest wait in ⋯.
- Mailboxes → Edit: show, hide and reorder mailboxes and labels.
Reading
- Designed mail fits the screen with a Dark mode mapped like Mail's; images, trackers and Unsubscribe share one line under the sender.
- Quoted history folds behind •••; plain-text mail gets the same rendering.
- Receipts, deliveries and bills show the amount, date and order number at the top, on any iPhone.
Intelligence, on the device only
- Rules sort first and work on every iPhone; with Apple Intelligence (Foundation Models), Corres refines Needs You and adds summaries, suggested replies and rewrites.
- Every summary and reason is checked against the email itself before you see it.
- There's no cloud fallback.
Private by design
- Sign-in is with your provider directly. Corres stores only revocable tokens or an app-specific password, in the Keychain.
- Remote images and tracking pixels are blocked until you choose to show them. Read receipts are never sent.
- No advertising or analytics code. Removing an account removes its mail from the device and from Spotlight.
- Your calendar is read only after you tap Check Your Calendar on an invitation, and only on the device.
- Settings → Send Diagnostics shares freeze and crash reports, never mail.
Gmail scopes
gmail.readonly, gmail.send, gmail.modify. gmail.send is a Google "sensitive" scope; gmail.readonly and gmail.modify are "restricted", so a public release needs Google's OAuth verification plus an annual CASA security assessment. See ADR 005 in Docs/Architecture.md.
Tech stack
- SwiftUI, iOS 17 and macOS 15 minimum (Liquid Glass and Foundation Models features on iOS 26 and macOS 26), Swift 6 strict concurrency, with AppKit where the Mac needs it.
- Apple frameworks rather than dependencies: SwiftData, Foundation Models, Core Spotlight, EventKit, WidgetKit, App Intents.
CorresCore: a Swift package holding the provider-independent domain and persistence layer (SwiftData), tested on macOS.- One dependency: GoogleSignIn-iOS, for Google sign-in. Microsoft sign-in uses the system web sheet, and IMAP and SMTP are our own (Postwright).
- Swift Testing for the domain suite.
Running locally
Open Corres.xcodeproj in Xcode, select the Corres scheme and a simulator or your iPhone (or CorresMac for the Mac app), then Run. For a device, set your team in Signing & Capabilities. Without an account, Corres opens with fictional sample mail, including an invitation to answer.
xcodebuild -scheme Corres -destination 'generic/platform=iOS Simulator' build
xcodebuild -scheme CorresMac -destination 'platform=macOS' build
The checked-in Corres.xcodeproj is the source of truth (it carries entitlements, the widget extension and embed phases that Scripts/generate_project.py predates, so don't regenerate from that script). Add new files through Xcode, or with Scripts/pbxtool.py add-sources <Corres|CorresMac> <paths…>. The app icon and launch mark are rendered from the vector mark by Scripts/RenderIcon.swift.
Running tests
swift test --build-path /tmp/corres-swift-build
cd Packages/Postwright && swift test --build-path /tmp/postwright-build
The first runs the domain suite (232 tests), the second the mail engine's (49). The separate build path avoids a code-signing quirk when the repository lives in a synced folder.
Releasing
- TestFlight beta:
Scripts/testflight.sh for iPhone and iPad, Scripts/testflight-mac.sh for the Mac (same App Store record, macOS added as a platform; the two share one build counter). Beta builds include Pro for testers (-D CORRES_BETA, and only when installed from TestFlight or Xcode, never from the App Store).
- App Store:
Scripts/appstore.sh, and submit that build number for review. Never submit a TestFlight beta build: App Review runs in the sandbox too, so the reviewer would get free Pro and the review would be rejected. The script refuses to upload if the beta flag got in.
Product specification · Architecture decisions · Design system · Research · Verification record
