1 Best APIs for Email (Paid) in Nigeria

OneSignal is the world's most widely used customer engagement platform for push notifications, in-app messaging, SMS, and email. Founded in 2014 and headquartered in San Mateo, California, OneSignal powers push notifications for hundreds of thousands of applications worldwide with over 1 million developers on the platform. The service's free tier — offering unlimited push notifications at no cost — has made it the default choice for countless Nigerian mobile and web app developers who need professional push notification infrastructure without budget constraints. For Nigerian developers and businesses, OneSignal is particularly compelling because the free plan has no limits on push notification volume. Unlike most SaaS platforms that limit free tier capacity, OneSignal's free plan allows sending unlimited push notifications to unlimited devices. The only significant features gated to paid plans are email, SMS, advanced A/B testing, automation, and dedicated support. For a Nigerian app focused purely on push notifications, the free plan is sufficient indefinitely regardless of scale. Push notification support covers all three major platforms — Android (via FCM/Google), iOS (via Apple Push Notification Service), and Web browsers (Chrome, Firefox, Edge, Safari). Nigerian apps targeting the predominantly Android market can send to Android users immediately; iOS support requires Apple Developer Program membership and certificate setup. Web push for Nigerian websites works in all major desktop browsers and Android Chrome, reaching users even when they're not actively browsing the site. User segmentation is one of OneSignal's most powerful features for Nigerian businesses. Rather than sending the same notification to every user, businesses can target specific segments — users in Lagos, users who haven't opened the app in 7 days, users who have made a purchase, users at a specific stage of an onboarding funnel. OneSignal builds user profiles automatically from events and attributes tracked in the app, and the dashboard provides visual segment builders that non-developers can use to target specific user groups. For Nigerian e-commerce apps, this means sending "Eko Mall flash sale" only to Lagos users, or re-engagement pushes only to users who haven't returned in two weeks. A/B testing for push notifications allows Nigerian businesses to test different notification content — two subject lines, two emoji variants, two delivery times — and automatically send the winning variant to the full audience. This data-driven optimization is typically only found in enterprise platforms, but OneSignal provides it even on the free plan (limited) and as a standard feature on paid plans. In-app messaging allows sending interactive messages that appear inside the app while the user is actively using it — as banners, pop-ups, or full-screen takeovers. Unlike push notifications (which work when the app is in the background), in-app messages target active users. Nigerian apps use in-app messaging for feature announcements, promotional offers to engaged users, feedback requests, and guided onboarding experiences. Automated journeys in OneSignal allow building multi-step notification sequences triggered by user actions or time delays. A Nigerian fintech app could build a journey: when a user registers → send welcome push on day 0 → if no transaction in 3 days, send "Make your first transfer" push on day 3 → if still no transaction after day 7, send SMS reminder → if transaction made, start "power user" journey. These journeys run automatically without manual intervention. SMS and email channels are available on paid plans, making OneSignal a potential all-in-one engagement platform for Nigerian businesses that want push, SMS, and email from a single system with unified user profiles and cross-channel journey automation. Integration with OneSignal requires adding the SDK to the mobile app (available for Swift, Kotlin, React Native, Flutter, Ionic, Cordova, and Unity) or a single JavaScript snippet for web push. Setup typically takes under an hour for a basic integration. The REST API allows server-side sending for programmatic notification triggers — a Nigerian server can call the OneSignal API to push a notification when an order status changes, a transaction completes, or any application event occurs.