MailFlare — unmissable alerts for the email that matters

A macOS menu bar app that puts an unmissable alert on screen when an important email arrives in Gmail.

What it does

You tell MailFlare which senders, domains, or subject keywords matter: your manager, your on-call paging service, a customer escalation list. When a matching message arrives in Gmail, MailFlare shows an alert with who it's from and the subject, and keeps it there until you dismiss it or open the message. The preview stays hidden until you choose Show Preview, so a stranger's words never fill your screen; you can turn that off in Settings, or hide the subject too.

By default the alert is a card on the display you're using. You can switch to a banner across the top of every display, or a full-screen alert on every display.

Because the alert is a real app window rather than a notification, Focus modes, Do Not Disturb, and notification settings don't suppress it. That's the point: for the handful of messages you genuinely must not miss, "I had notifications off" stops being a reason.

How it works

You sign in with your Google account. MailFlare requests read-only access to Gmail; it cannot send, modify, or delete anything.
Every 30 seconds by default (as often as every 15 seconds if you choose), it asks Gmail for new unread messages and checks their sender and subject against your rules.
Everything happens on your Mac. MailFlare has no servers; your email never leaves your computer and is never shared with anyone.
If Gmail can't confirm that a sender is really who the address says, the alert tells you, and a rule can be set to alert only for verified senders. The "My bank" rule starts that way, so a forged bank email can't set off an alert.
Quiet hours keep alerts off overnight, and you can pause alerts for 30 minutes, an hour, until 9 AM tomorrow, or until you resume them.

Privacy in one sentence: MailFlare reads the sender, subject, and preview of new mail on your Mac to decide whether to alert you, looks at who's in your recent mail only to suggest people while you set up rules, keeps message IDs but never message content, stores your sign-in token in the macOS Keychain, and sends nothing anywhere. Full details in the Privacy Policy.

Requirements

macOS 14 (Sonoma) or later, and a Gmail or Google Workspace account.