Space CRM / Blog
Transactional Email Best Practices: OTPs, Receipts, and Notifications That Always Deliver
How to set up transactional email infrastructure correctly so critical emails never land in spam.
Transactional vs marketing email — keep them separate
Sending OTPs through the same infrastructure as bulk campaigns risks deliverability contamination. One spam complaint on a campaign can delay a customer's OTP.
Use a dedicated transactional sending domain and IP pool so your most critical emails are never affected by marketing performance.
Integrating the SpaceCRM Send API
Authentication via API key, a single POST endpoint, and webhook callbacks for delivery events. Integration takes under 30 minutes in any language.
Use the API for OTPs, welcome emails, password resets, order confirmations, and notifications. Every send is logged with full event history.
Monitoring critical email delivery
Set up webhook listeners for bounce and complaint events. A 2%+ bounce rate on transactional email needs immediate attention.
Monitor OTP delivery time specifically. Users expect OTPs in under 10 seconds. If p95 delivery exceeds 30 seconds, review your sending infrastructure.
