Behind the sending of marketing emails lies a vast array of mechanisms and tools essential for the success of the campaign being implemented. Among these, the SMTP relay (“Simple Mail Transfer Protocol”) ensures that messages reach their destination. An essential component, yet its functioning remains a mystery for many marketers. How does it work, and why is it indispensable in a communication strategy? This article explains what you need to know about this SMTP relay.
What is the SMTP relay?
The SMTP relay (“Simple Mail Transfer Protocol”) is a service that allows emails to be transmitted from a sender to a recipient via a server. It acts as an intermediary, handling the transfer of messages between different servers until they reach their final destination. To simplify, it can be compared to a postal service that ensures electronic mail goes through the right steps to reach its recipient.
The SMTP relay is based on the SMTP protocol, a universal standard that defines the rules of communication between servers for sending and receiving emails. Therefore, the SMTP protocol represents the technical framework, while the SMTP relay represents the concrete application of these rules to route messages between servers.
Why is the SMTP relay important in email marketing?
Ensure deliverability
The SMTP relay verifies recipients’ email addresses and facilitates message transmission by avoiding blockages related to technical or configuration problems. If your company sends a large volume of emails, whether newsletters, promotional campaigns, or transactional emails, it thus ensures smooth management and better deliverability.
Improve sending reputation
Using a trusted SMTP relay helps improve the IP address and domain reputation of the sender. This helps prevent emails from being marked as spam. It can be particularly useful if you are experiencing spam ranking issues or low delivery rates.
Manage large volumes
Marketing campaigns often involve massive email sending. An SMTP relay allows managing these volumes by ensuring smooth and fast transmission.
Provide accurate reports
SMTP services often offer analytic tools that allow tracking delivery, opening, and click rates, essential elements for optimizing your campaigns.
How does the SMTP relay work?
The SMTP relay process begins with the submission of an email by a user or a sending application. Once the email is sent, the SMTP server verifies the sender’s information to ensure they are authorized to transmit the message. If authenticated, the message is forwarded to an SMTP server that acts as a relay.
Then, the SMTP server identifies the final mail server corresponding to the recipient’s domain. For example, for an address ending in @gmail.com, the message will be routed to Google’s servers. Once this match is made, the message is transmitted to the recipient server, which performs the final step of delivering it to the end user’s inbox.
This smooth process relies on a well-defined architecture, where each step ensures that the email reaches its destination unimpeded, while complying with the standards established by the SMTP protocol.
In summary:
Message submission / Transfer to the intermediary server / Routing to the recipient server / Final delivery. This process relies on a well-defined architecture, where each step ensures that the email reaches its destination unimpeded, while complying with the standards established by the SMTP protocol.
The advantages of using a third-party SMTP relay service
Many companies choose to use third-party SMTP relay services rather than rely on their own infrastructure. Indeed, these offer great reliability thanks to infrastructures specifically designed for handling emails. These solutions are also compatible with a multitude of platforms and marketing tools, facilitating integration and use. Moreover, in case of problems, third-party providers offer dedicated technical support, reducing the risks of campaign interruptions. Finally, they include advanced features for managing bounces and minimizing spam risks, thereby ensuring effective and professional communication.
Best practices for using an SMTP relay
To make the most of an SMTP relay in your email marketing strategies, here are some tips:
- Choose a reliable provider – Opt for recognized services such as Sarbacane, Brevo, SendGrid, Mailgun, or Amazon SES. They offer proven reliability and advanced features.
- Authenticate your emails – Implement protocols like SPF, DKIM, and DMARC to prevent phishing and improve deliverability.
- Monitor your performance – Regularly analyze reports to identify potential issues and optimize your campaigns.
- Comply with regulations – Ensure compliance with data protection laws, like GDPR, by obtaining recipients’ explicit consent.
The SMTP relay is an indispensable tool for any email marketing strategy. It not only ensures message delivery but also better management of sending reputation and the overall performance of your campaigns. Do not hesitate to explore third-party SMTP relay services to benefit from support tailored to your needs.
