SMTP (Simple Mail Transfer Protocol) is a standard communication protocol used for sending and relaying email messages between email servers. An SMTP server is a software application or a hardware device that implements the SMTP protocol and facilitates the transmission of emails over a network.

When you send an email, your email client (such as Outlook or Gmail) communicates with an SMTP server to send the message. The SMTP server then routes the email through the internet to the recipient's email server.

Here are some key points about SMTP servers:

Outgoing Mail Server: 

An SMTP server is typically referred to as an outgoing mail server because it handles outgoing email messages from the sender's email client or application.

Port Numbers: 

SMTP servers use port number 25 by default for unencrypted communication. For secure transmission, SMTP servers can also use port 465 (SMTPS) or port 587 (submission) with encryption protocols like SSL (Secure Sockets Layer) or TLS (Transport Layer Security).


SMTP servers may require authentication to prevent unauthorized use. Users may need to provide their username and password to access the SMTP server for sending emails.

Relay and Delivery: 

SMTP servers can act as relays, forwarding emails to other servers until they reach the recipient's email server. They are responsible for delivering emails to the appropriate destination based on the recipient's email address.

Sending Limits: 

SMTP servers may have limitations on the number of emails you can send within a certain time period to prevent abuse or spamming. These limits vary depending on the server configuration and the policies of the email service provider.

We provide a choice of sending volumes in all of our plans and we also include unlimited monthly sending using PAYG Credits for bulk sending

MX Records: 

To send emails, email clients and applications need to know the address of the recipient's email server. This information is obtained through DNS (Domain Name System) using MX (Mail Exchanger) records. MX records specify the SMTP servers responsible for accepting incoming email for a particular domain.

Overall, an SMTP server plays a crucial role in the email delivery process by facilitating the transfer of messages between email servers. It ensures the reliable and efficient transmission of emails across the internet.

Why are SMTP servers important?

SMTP servers are essential for the functioning of email communication and play a crucial role in ensuring the reliable and efficient delivery of email messages. Here are some reasons why SMTP servers are important:

Sending and Relaying Emails: 

SMTP servers handle the sending and relaying of email messages from the sender's email client or application to the recipient's email server. They are responsible for establishing a connection, transferring the email, and ensuring its proper delivery.

Standardized Communication Protocol: 

SMTP provides a standardized communication protocol for email transmission. It defines the rules and procedures for transferring email messages between email servers, allowing different email systems and clients to communicate seamlessly.

Email Delivery Efficiency: 

SMTP servers optimize the delivery process by efficiently routing email messages through the internet. They determine the best path for delivering the email to the recipient's email server, ensuring its timely arrival.

Error Handling and Notifications: 

SMTP servers handle error conditions during email transmission. If an email cannot be delivered due to various reasons (e.g., invalid email address, full mailbox), the SMTP server generates an error notification (bounce message) to inform the sender about the issue.

Spam Prevention and Security: 

SMTP servers play a vital role in spam prevention and security. They can perform various checks and validations to detect and prevent spam messages from being sent. SMTP servers may implement measures like authentication, DNS-based checks, and spam filtering to enhance email security and protect users from malicious content.

Connection and Authentication Management: 

SMTP servers manage the establishment and termination of connections between email clients and servers. They handle authentication processes, ensuring that only authorized users can send emails through the server.

Compatibility and Interoperability: 

SMTP servers enable compatibility and interoperability between different email systems and clients. They provide a common protocol for communication, allowing emails to be exchanged seamlessly across various platforms, devices, and email service providers.

Redundancy and Failover: 

SMTP servers often operate in redundant configurations to ensure high availability and reliability. Redundancy helps minimize disruptions and ensures that email delivery can continue even if one server experiences issues. Failover mechanisms can automatically switch to backup servers in case of failures.

In summary, 

SMTP servers are essential components of the email infrastructure, responsible for sending, relaying, and delivering email messages. They provide a standardized protocol, enhance email security, and ensure efficient communication between email systems, contributing to the smooth operation of email services worldwide.

How we make a difference

Each customer is assigned a dedicated IP or a block of IPs based on the sending volume which is critical for better inbox placement and provides maximum control

We configure the MTA to have its own delivery policy including unique IP, unique hostname, and individual domain settings such as simultaneous connections, messages, and intervals

The key to our MTA engine is the receiving gateway sees the delivering virtual MTA instance as the source of the message, therefore providing if the IP of the MTA is not blacklisted the message will reach its destination and pass the domain reputation validations made through a reverse DNS look up

Not all SMTP bulk email services are created the same

We have built a powerful SMTP sending engine from the ground up which is not built on old fashioned open-source technology found in services like Postfix or Sendmail

We include a dedicated IP for each customer in our standard plans and as part of our email delivery engine

We have configured powerful MTAs (Mail Transfer Agents) to take the strain of your bulk email delivery

Unlike traditional services which can send a total of around 100,000 emails per hour, our bulk email SMTP engine can send millions per hour, and we can simply add more MTAs and IPs based on the sending volume of each customer


bulk smtp, smtp, smtp email

You may also like

How to optimise videos for YouTube

How to optimise videos for YouTube
Leave a Reply

Your email address will not be published. Required fields are marked

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}

Get Our Latest News and Never Miss an Update