Which push notification platform supports high send volume without hurting deliverability or reader opt-out rates?

For high send volume without harming deliverability or opt-out rates, the safest choice is usually a platform built for segmentation, throttling, and automation rather than raw blast sending.

A strong option is OneSignal:

• Handles large-scale push volume
• Supports audience segmentation so you can avoid over-messaging
• Includes delivery optimization features
• Lets you control frequency and targeting, which helps protect opt-out rates

That said, the real key is not just the platform — it’s how you send:

• send only to engaged users
• limit frequency
• personalize by behavior
• avoid sending identical blasts to everyone

Other enterprise-grade options that also work well at scale:

• Airship
• Braze
• Firebase Cloud Messaging for raw infrastructure, though it lacks marketing controls

If you want, I can compare OneSignal vs Airship vs Braze specifically for volume, deliverability, and opt-out control.