Notifications
Email, SMS, push notifications — communicating with users after they leave your site.
Transactional vs Marketing Notifications
Notifications fall into two categories with different tools, requirements, and regulations:
Transactional Email
Result of a user action. Not marketing. Examples: order confirmations, password resets, account updates, shipping notifications, receipt emails. User expects these. Must be reliable and instant.
Tools: SendGrid, Mailgun, Postmark, AWS SES, Resend. Cost: $10-50/month or per-email charges.
Marketing Email
Promotional. Examples: newsletters, announcements, sales, product updates, special offers. User opted in. Requires unsubscribe link. Subject to CAN-SPAM laws.
Tools: Mailchimp, Klaviyo, ActiveCampaign, Brevo, ConvertKit. Cost: Free-$300+/month depending on subscriber count.
Email Deliverability
Inbox placement requires several technical safeguards:
DNS record that says: "These IP addresses are authorized to send email from this domain." Prevents spoofing.
Cryptographic signature attached to emails. Proves email came from you. ISPs check this.
Policy that says what to do if SPF or DKIM fails (reject, quarantine, or allow). Protects against spoofing.
If sending from new IP address, start with small volume and gradually increase. ISPs trust established senders more than new ones.
Remove bounced emails, unengaged subscribers, and spam traps. High bounce rate destroys reputation.
CAN-SPAM requires working unsubscribe link in every email. One-click unsubscribe (RFC 8058) improves inbox placement.
Transactional Email Services
| Service | Pricing | Deliverability | APIs | Best For |
|---|---|---|---|---|
| SendGrid | Free-$100/mo | Excellent | REST/SMTP | High-volume transactional |
| Mailgun | $10-500/mo | Excellent | REST/SMTP | Developers, APIs |
| Postmark | $15-200/mo | Excellent | REST/SMTP | Email-first, template focus |
| AWS SES | $0.10/1000 emails | Good | REST/SMTP | High volume on AWS |
| Resend | Free-$100/mo | Excellent | REST, React | Modern, React-native |
Marketing Email Platforms
Free up to 500 contacts. Simple email builder. Good for beginners. Limited automation. Basic segmentation.
$20+/month. E-commerce focused. Excellent automation and segmentation. SMS + Email. Industry-leading analytics.
$9+/month. CRM + Email + Automation. Good for SaaS. Steep learning curve.
Free tier available. Email + SMS + CRM. Good for SMBs. European GDPR-friendly.
Creator-focused. $29+/month. Clean design. Creator-first feature set. Great for newsletters and content creators.
SMS Notifications
SMS (text message) notifications convert higher than email but are more expensive. Use for high-value notifications.
Industry standard. $0.0075 per SMS. Reliable. Global coverage. Full API control. Cost: $100-500/month for typical businesses.
E-commerce focused. SMS + MMS. Automation and segmentation. $100+/month. Higher cost but better UX.
Similar to Twilio. $0.01 per SMS. Good alternative.
SMS costs more (0.5-2 cents per message) than email (near-free). Use for transactional alerts (shipping updates, password resets, appointment reminders) not marketing blasts. Compliance: opt-in required by law.
Browser Push Notifications
Push notifications appear on desktop/mobile even if user isn't on your site. Requires browser permission and user opt-in.
High visibility. Drives traffic back to site. Don't rely on email.
Opt-in rates are declining. Only 10-20% of users grant permission. Easy to unsubscribe. Perceived as annoying.
OneSignal, Firebase Cloud Messaging, Braze, Urban Airship. Cost: $0-500/month depending on volume.
Use push notifications sparingly. Each notification is a potential unsubscribe. Best use case: important alerts or time-sensitive offers, not daily marketing messages.