Relai-Smtp.com provides a professional SMTP gateway and email relay service for businesses and other senders seeking flexible, usage-based email delivery. Instead of monthly subscriptions or fixed-volume plans, customers purchase recipient tokens and are charged according to the number of recipients they email. Tokens remain valid for two years, and a free pack of 500 recipients is available, with a free credit offered once per month. There is no minimum monthly volume, and accounts can be recharged as needed.

The service supports SMTP account authentication or relay access based on the sending IP address, and can be used over broadband, fiber, or mobile connections. Its servers use IPv4 and IPv6 and are hosted in France. Features include support for SPF, DKIM, and DMARC, secure connections through SSL, STARTTLS, and MTA-STS, real-time delivery statistics, and a comprehensive API. Relai-Smtp.com also provides private bounce management and relaying of abuse notifications. Pricing is tiered by token volume, with setup fees waived; customers requiring more than 10 million recipients are invited to contact the provider.