Are you wondering which SMTP port to use for better email deliverability (ports 25, 587, 465, or 2525)? Don’t worry! This article will help you choose the right one.

You’ve probably heard that email is the best way to reach your customers. It’s a great way to keep in touch and let them know about your latest products and promotions. But what if your email isn’t reaching their inbox?

Many factors can affect whether your email lands in your customers’ inboxes or ends up in their spam folders. One of the most important factors is the port your SMTP server is using.

How to choose tight smtp port

In this article, we’ll explain SMTP ports and how to choose the right one for your business. We’ll also share some tips on how to prevent your emails from being sent to spam.

What Is SMTP and What Is an SMTP Port

SMTP stands for Simple Mail Transfer Protocol. It is a set of rules that mail servers use to send and deliver emails over the Internet. You can think of SMTP as a mailman who delivers letters from one house to another.

On the other hand, an SMTP port is a unique phone extension/number in a large office. Each phone extension/number belongs to a different employee or department within the office. Calling the main number of the office does not guarantee that you will reach the person you want to talk to, as the call might be transferred to the wrong extension or go to voicemail. Instead, you must dial the specific phone number/extension of the person or department you want to contact.

Similarly, a mail server that does not specify a port may be unable to handle network data. But, a mail server can receive data only on a specific port and send it to the right application.

SMTP uses different ports for different reasons and at different times. These SMTP relay ports include ports 25, 465, 587, and 2525.

Types of Ports Used in SMTP

There are three types of ports used in SMTP:

  • The standard port, which is 25
  • The secure port, which is 465
  • The extended security port, which is 587
  • The alternative of 587, port 2525

The standard port is the most common and default for most email clients. However, secure and extended security ports are recommended for senders who require a higher level of security.

types of smtp

Which SMTP Port Should You Choose (Port 25, 587, 465, or 2525)?

Now that you understand the different SMTP ports, it’s time to choose the right one for your needs. You’ll need to use a different port depending on your email client and server.

You’ll need to contact your email service provider (ESP) or system administrator to find out which port to use. They can tell you which port to use for your specific setup. Once you have that information, enter it into the SMTP port field in your email client.

Factors That Influence Port Selection

When it comes to selecting the right port, there are several different factors to consider. For example, the connection type (Secure or Non-secure) as well as the authentication type (TLS or SSL). There’s also the authentication protocol and whether you’re using a shared server or a dedicated server.

Depending on your user’s email provider, some ports may not be available. It would be best to remember that different ports will have different connection speeds. For instance, port 25 is a non-secure port faster than Secure ports like 465 and 587.

You should also consider why you’re using SMTP first: Is it for marketing emails, transactional emails, or email notifications? Different ports may offer advantages for each of these scenarios. For example, if you are sending out marketing emails, then port 25 may provide better speed and reliability, whereas dedicated servers use secure encrypted ports like 465 and 587.

It’s essential to carefully weigh these variables to choose the best port for your use case.

The Four Most Common SMTP Ports and Their Use Cases

When configuring your SMTP settings, you need to know about the various ports available and which is the best for your setup. Here are some of the most commonly used ports and what they’re typically used for:

  • Port 25: This is the default port for standard SMTP communication. It’s used to send emails over a non-secure connection.
  • Port 465: Also known as the Secure SMTP (SMTPS) port, this port is used to send emails over a secure SSL or TLS connection.
  • Port 587: This port is used for submission with authentication and is often used with webmail providers. It is recommended that you use this port with TLS/SSL encryption when sending outbound messages, as it works well with most LAN setups.
  • Port 2525: This port provides an alternate way of sending emails if other ports are blocked or restricted.
common ports

Each of these ports has its own pros and cons, so it’s essential to consider your setup before deciding which one to use. For example, if you have an email server on site, port 25 or port 587 may be sufficient for outgoing mail, whereas if you use an external provider, port 465 or port 2525 may be more suitable.

Security Considerations When Choosing an SMTP Port

When selecting an SMTP port, security should also be a consideration. Different ports have different levels of security, so it is vital to choose the correct port for your needs. For example, sending sensitive information like credit card numbers or passwords should use a secure port like TLS (Transport Layer Security). This port uses encryption to protect the data, making it more difficult for hackers to intercept.

You can also consider using an email authentication protocol such as Sender Policy Framework (SPF) or DomainKeys Identified Mail (DKIM). These protocols will ensure that the emails are being sent from a legitimate source and can help protect against spoofing and phishing attacks. Finally, ensure that your server supports a secure sockets layer (SSL) or Transport Layer Security (TLS). SSL/TLS is a technology that encrypts data over the internet and helps keep your emails safe from eavesdroppers.

Final Words

So, how do you choose the right SMTP port?

Well, the first step is to identify the type of connection your mail server is using. Once you know that, you can then find the corresponding port number.

If you’re unsure how to do that or are experiencing difficulty setting up your SMTP port, speak to your mail server provider for help. They should be able to guide you in the right direction.

Choosing the correct SMTP port can be tricky, but it’s not too difficult with the right information. Just make sure you stay informed and consult with your mail server provider if you need assistance.

Frequently Asked Question

Should I use port 465 or 587?

Port 465 and port 587 are used for SMTPS, which is SMTP with encryption and authentication. Initially, port 465 was assigned for SMTPS, but in 1998, it was deprecated and replaced by port 587. However, some email service providers still support port 465 for backward compatibility. The official recommended port for SMTPS is 587. You should only use port 465 if your network provider or firewall blocks port 587.

Is port 587 safe?

Port 587 is safe as it’s the only method of ensuring secure SMTP, which means that by using TLS encryption, you can initiate a secure connection with the mail server. As a result, you can encrypt your email data and prevent anyone from intercepting or tampering with it.

Is SMTP port 25 Secure?

SMTP port 25 is not secure because it does not use encryption or authentication. Also, most spammers and hackers use port 25 to send unsolicited or malicious emails. Therefore, most internet service providers (ISPs) and email service providers (ESPs) have blocked or restricted port 25 to prevent spam and abuse.

What is the port 587 used for?

Port 587 is used for SMTP submissions, which is how you send emails from an application or client to a server. Port 587 supports SMTPS, which supports TLS encryption and authentication to secure email transmission.

Is port 587 open by default?

Port 587 is the default port for mail submission because it works with all kinds of SMTP data transmission, and almost every email provider supports it.

Why is SMTP port 25 blocked?

SMTP port 25 is blocked by most internet service providers (ISPs) and email service providers (ESPs) because many spammers and hackers use it for spamming. 

Should I use port 25 or 587 for SMTP?

You should use port 587 for SMTP instead of port 25. Port 587 is the standard SMTP submission port, which sends emails from an email client or application to a mail server. Also, Port 587 supports SMTPS, which means it can use encryption and authentication to secure email transmission.