It was this one, simple-sounding requirement: "The app must get new mail instantly, without killing the user's battery."
This is the central nightmare of modern Android development. How do you build a fast and smart mail client when the OS (Doze, Standby Buckets) is actively trying to kill your background processes?
Here's a look at the technical challenge of building a reliable sync engine for a Mail App.
The "Obvious" Solution (That Fails)
"Just use a Foreground Service!" This is the brute-force method. Sure, it keeps your app alive. It also puts a permanent, ugly notification in the user's tray and is a guaranteed way to drain their battery. This is not how you build the best email app for Android
The "Correct" Solution (That's Hard)
The "correct" way is to use Work Manager. But Work Manager isn't designed for "instant." It's designed for "opportunistic" work.
The real challenge is handling a multiple email account app architecture:
Challenge 1: IMAP IDLE: The best way to get instant email is an IMAP IDLE connection, which is a persistent, long-lived connection. This is exactly what Android tries to prevent.
Challenge 2: Multiple Providers: Handling the sync for Gmail Outlook in one app means handling multiple, separate long-lived connections.
Challenge 3: OEMS: Samsung, OnePlus, Xiaomi... every OEM has its own battery "optimization" that kills your app, even if you use WorkManager perfectly.
The Solution We Built
We had to find a hybrid approach.
Intelligent Sync: We use Work Manager for a reliable "fetch" every 15-30 minutes. This is the fallback. It ensures that even if the OS kills the app, the user will get their mail.
Lightweight Foreground Service (The Smart Way): We do use a Foreground Service for IMAP IDLE, but only when the user is on Wi-Fi and the phone is charging. The service is killed immediately once those conditions aren't met.
Focus on "One Inbox": By syncing all all email accounts to one local database, we only have to run one process. This is the power of a true Unified Inbox The app's job is to sync the database, not to run 5 separate apps.
This approach is what allows our All mail App called "mail App - All Mail Anywhere" to manage all email without being a battery hog.
It's a free email app that gives you all mail access to all email providers in one inbox for all accounts and it was a technical beast to build.
You can check out the final app here: https://play.google.com/store/apps/details/id=com.allmail.anywhere.inbox
Top comments (0)