SMTP Server: What Is It and What Is It Used For?

The SMTP server is the acronym used to refer to the “Simple Mail Transfer Protocol.”

What does SMTP mean? Literally, it translates as a simple protocol for sending emails. In reality, it is the protocol used to transfer emails to messaging servers. In computing terminology, SMTP is also used to refer to the servers and relays involved in the transmission of these emails.

What is an SMTP server and what is it used for?

Nowadays, a vast number of emails are sent every day. The transfer of electronic messages relies on a specific process: SMTP, one of the most widely used computer protocols since the invention of email. What is SMTP? What does SMTP stand for? What is it used for? These are the questions this article will answer in the following lines.

What You Really Need to Know About the SMTP Server Protocol

What is the definition of the SMTP protocol?
First of all, it’s important to understand that SMTP (Simple Mail Transfer Protocol) is a communication protocol that defines the rules for sending emails to mail servers. Its operating model is fairly straightforward.

To function properly, the sender and the potential recipients of the message must be specified. Their existence is then verified. If they are confirmed to exist within the network, the body of the message is quickly transmitted to them.

What Are the Necessary Steps to Transfer Mail Using an SMTP Server?

The journey of an email can be broken down into four main stages:

1. Stage 1: Transmission begins from the sender’s MUA (Mail User Agent) to the transmitting server using the SMTP protocol.

2. Stage 2: The email is transferred from one MTA (Mail Transfer Agent) to another until it reaches the recipient’s MTA. This stage also relies on SMTP.

3. Stage 3: The message is passed from the MTA to the MDA (Mail Delivery Agent), where it is stored for retrieval.

4. Stage 4: The recipient’s MUA sends a request to the MDA to retrieve the message.

What Is an SMTP Relay?

Technical discussions often refer to this concept. An SMTP relay refers to the process of forwarding an email to its destination server. However, this term also applies to the servers that handle the transfer of emails from sender to recipient. In this context, “SMTP relay” is effectively synonymous with SMTP server.

What Is an SMTP Server?

An SMTP server is the system or tool used to send emails to a designated recipient server. This process, of course, relies on the Simple Mail Transfer Protocol. Since several servers can be involved in relaying a single message, an SMTP server is often one of many handling the delivery of a single email.

SMTP Servers and Email Deliverability

Understanding SMTP servers also involves understanding email deliverability. The SMTP server used to send emails is linked to a specific IP address. This address plays a critical role in deliverability, as it helps internet service providers (ISPs) determine the reputation of the sender.

Free or basic webmail SMTP servers are generally not suitable for sending large volumes of emails. These servers may share IP addresses with spammers, reducing your chances of landing in the inbox and increasing the likelihood of your emails being marked as spam.

What Is the Best SMTP Server Solution?

For optimal deliverability, it is essential to use professional SMTP servers that are specifically configured for bulk email delivery. Today, many specialized companies provide such services.

The SMTP servers are hosted on reliable, robust infrastructure. They can send millions of emails per day, and their IP addresses are closely monitored and managed to ensure high deliverability with major ISPs.

These servers are perfect for marketing campaigns and transactional emails alike. With a professional SMTP server, you can track email sending statistics in real time, including:

• Open rates

• Click-through rates

• Bounce rates

• Spam complaints

• Unsubscribe requests

For even greater deliverability control, you can use a dedicated IP SMTP server, ideal for businesses running targeted email marketing campaigns.

IMAP and POP3: Two Protocols to Receive Your Emails

Alongside SMTP, which handles sending, IMAP (Internet Message Access Protocol) and POP3 (Post Office Protocol version 3) are the two main protocols used to receive emails.

Gmail supports both IMAP and POP3. To enable one of these protocols, log into your Gmail account, go to Settings by clicking on the gear icon, and select See all settings. In the Forwarding and POP/IMAP tab, you can activate IMAP or POP access according to your preferences.

Note: IMAP is generally recommended for smooth synchronization across multiple devices.

• IMAP: This protocol allows you to read your emails directly on the mail server without downloading them locally. Your messages stay synchronized across all your devices (desktop, smartphone, tablet), making it perfect if you access email from various devices.

• POP3: By contrast, POP3 downloads the email to a single device and usually deletes it from the server after that. This means your emails are only accessible from the device on which they were downloaded, which can be a drawback if you use several devices.

To further improve deliverability, businesses can also use SMTP servers with dedicated IPs, providing more control over large-scale email campaigns.

FAQ – SMTP Server

What is the difference between SMTP, IMAP, and POP3?
SMTP (Simple Mail Transfer Protocol) is used for sending emails, while IMAP and POP3 are for receiving them. IMAP keeps messages on the server and allows access from multiple devices. POP3 downloads messages to a single device and typically deletes them from the server afterward.

How do I configure an SMTP server in an email marketing platform?
To configure an SMTP server, you need to provide the SMTP server address (e.g., smtp.gmail.com), the correct port, a username, and a password. Some tools, like ActiveTrail, integrate this configuration automatically.

Should I use IMAP or POP3 to read my emails?
Use IMAP if you check your email on multiple devices—it keeps everything synchronized. POP3 is better suited for users who access email from only one device and want to store emails locally.

Is it secure to use SMTP to send emails?
Yes, as long as you use secure versions of the protocol (SMTPS), which include SSL or TLS encryption, along with strong authentication. This helps protect against interception and email spoofing.