Native provider push
When supported, BlueMail subscribes to the provider's own push channel and receives an event the moment a new message arrives.
Engineering · Instant Push
How Instant Push actually works.
A technical look at the architecture behind BlueMail's real-time email delivery — no polling, no delay, no battery cost.
The problem with polling
Most email clients still rely on polling: checking your provider every few minutes for new mail. Polling wastes battery, generates needless network traffic and introduces a delay between when a message arrives and when you see it.
How BlueMail does it
BlueMail's Instant Push uses a hybrid architecture: native push from providers that support it (Gmail, Outlook, Office 365, FastMail, iCloud, Exchange and any provider with IMAP IDLE) and a thin BlueMail relay for providers that don't.
IMAP IDLE
For providers without a push API, BlueMail keeps a long-lived IDLE connection open and receives a server-pushed notification in real time.
BlueMail relay
For legacy providers, our lightweight relay holds a single connection per account and pushes events to your device through FCM or APNs.
What about privacy?
The relay only stores enough state to detect change events: a message ID and timestamp. It never sees message content, subject, body or attachments. End-to-end encryption (PGP, S/MIME) is unaffected.
Battery and bandwidth
Because each device holds at most one persistent connection (multiplexed across accounts), overall network and battery usage is dramatically lower than polling. Most users see < 1% of daily battery attributed to BlueMail's background activity.