When it comes to email marketing, using SMTP servers is important to ensure smooth operation and experience improved outcomes.
They play a vital role in sending and delivering email messages to the right recipient without being marked as spam. However, choosing the right SMTP port is necessary to avoid glitches and ensure good connectivity.
In this post, we will discuss the common SMTP ports namely 25, 465, and 587 helping you choose the best port based on your needs. Additionally, we will also have a quick look at why it is important to choose the right SMTP port. Let us start with a brief introduction to SMTP ports.
What Are SMTP Ports?
SMTP ports are communication endpoints that manage the transfer of information from one server to another. The role of SMTP ports is to ensure that the correct email data is being transferred to the right place.
As SMTP uses different protocols to ensure safe and smooth communication, different ports are designed for specific protocols and their associated functions. These ports serve as unique codes of a mobile number to ensure that the call is transferred to the right person.
What is the Need for Different SMTP Ports?
When you send emails from one client to another, there are different steps associated with this process. For example, the first step is to submit an email from your client to the mail server.
Next, the message is relayed from one server to another to ensure it reaches the recipient’s email client. Here, each step requires a different port to complete the process.
What Are the Different Types of SMTP Ports and Their Functions?
If we talk about SMTP ports, there are three commonly used ones:
- SMTP Port 25
- SMTP Port 465
- SMTP Port 587
All these have different functions and each one solves a different purpose. Let us see one by one:
SMTP Port 25 – The Standard/Original SMTP Port
Port 25 is known as the oldest and most well-known SMTP port. This port 25 is generally used for server-to-server email transmission. It was designated for email communication in 1982.
When one email server delivers a message to another server, port 25 comes into play. This is one of the most widely supported ports and is ideal for server-to-server transfers.
There is one drawback of port 25 as it is often blocked by ISPs to prevent spam. It supports open relay and hence, spammers use this for illegal activities. Additionally, port 25 is not ideal for email submission.
SMTP Port 587 – The Modern Submission Port
Also regarded as the default mail submission port, SMTP port 587 comes into play for submitting email messages to a server for delay. One of the best things about this port is that it supports advanced security features like StartTLS encryption.
This encryption allows users to upgrade an unencrypted connection to an encrypted one using TLS or SSL. SMTP port 587 is ideal for client-to-server communication.
One of the drawbacks that need attention about port 587 is that it requires proper configuration and may not work if blocked by a firewall.
SMTP Port 465 – The TLS Port
This port 465 was originally designated for SMTPS to provide a secure way to send emails.
However, this port was never published as an official SMTP port. Still, many email service providers support this port for encrypted email transmission. Hence, port 465 is widely used and supports SSL encryption.
One thing you must know about port 465 is that it may cause compatibility issues as it is not officially recognized.
Bonus: SMTP Port 2525 – The Alternative Port
Just like port 465, SMTP port 2525 is also not officially recognized. However, this port makes a good alternative to port 587 for SMTP submission when it is blocked.
This is because port 2525 is supported by most ISPs and cloud-hosting service providers for SMTP.
What is the Importance of Choosing the Right SMTP Port?
Just like choosing the right SMTP service provider is important, selecting the right SMTP port also holds the key to ensuring smooth, reliable, and secure email delivery.
If you choose the wrong port, certain issues may arise like blocked messages, failed transmissions, and security issues.
For instance, sending emails through port 25 from an email client might result in messages being rejected by ISPs, while neglecting encryption on port 587 could expose sensitive data to attackers.
The right port ensures that your emails are transmitted securely, are less likely to be flagged as spam, and can reach recipients without unnecessary delays or failures.
Final Thoughts
Understanding SMTP ports is key to configuring email systems effectively. While port 25 remains essential for server communication, ports 465 and 587 cater to secure email submission. In most cases, port 587 is the optimal choice for modern email clients.
With this knowledge, you can confidently configure your email services and navigate the complexities of SMTP with ease.
