No. apsd delivers notifications.
It keeps one persistent connection to Apple's push servers and delivers notifications for every app: Messages, Mail, Calendar, third-party apps and system services.
Instead of every app keeping its own connection open, macOS keeps one: apsd's link to Apple's push servers, using port 5223 or falling back to 443. In a network monitor you'll see a steady, mostly idle connection with small bursts as notifications arrive. Blocking it stops notifications, iMessage and some iCloud features from updating.
Facts
- Owner
- Apple (part of macOS)
- Network-related
- Yes
- Typical ports
- 5223, 443
- Block it?
- Don’t block it
What it connects to
| Host | Country | Purpose |
|---|---|---|
| courier.push.apple.com (port 5223 or 443) | Various | Push notifications for all apps |
Should you worry?
No. apsd delivers notifications. Its connection to Apple is meant to stay open all the time; that's how notifications arrive instantly without each app polling.
Frequently asked questions
What is apsd on a Mac?
The Apple Push Notification service daemon, which receives notifications for all apps over a single connection to Apple.
Why is apsd always connected?
Push notifications need a persistent connection so messages arrive instantly. It uses very little data while idle.
What port does apsd use?
TCP 5223 to Apple's push servers, with 443 as a fallback when 5223 is blocked.