Best SMTP Relay for Developers

Never worry about email deliverability,
IP reputation or blacklisting again.

Sign up FREE now and test-run CritSend with 1,000 emails

Reliable Inbox Delivery

  • Sends your transactional messages, invoices, newsletters, password reminders & more
  • Email Deliverability Engine enhances your mails for optimal inbox delivery
  • Automatic SPF & Domain Key authentication
  • Never worry about deliverability, maintaining your own mail server or your IP reputation again

Online Reporting & Alerts

  • View Sends, Opens, Click-Throughs, CTR, Spam Reports, ISP Blocks, & more
  • Quickly access statistics with Reports & custom Graphs
  • Full bounce & unsubscription management
  • Know which emails your recipients are reading, and which need improvement

Low Cost

  • Prices from $0.28 per 1,000 emails with no setup or consulting fees
    See all Prices
  • Pay-per-use pricing. No commitment required.
  • 24/7 support

Get Setup Within Minutes Just point to our enhanced SMTP relay and send or use our API

Learn more about integrating CritSend with