Learn How An SMTP Port Works With The Types Of SMTP Ports Used To Deliver Your Emails Efficiently

Sending an email is an elementary activity today. Type in the message you need to send, insert the address, and click on the ‘Send’ option. The mail reaches the recipient almost instantly. However, the email message goes through a series of steps before it actually reaches the recipient. This series of steps is the concept of SMTP. Let us understand what SMTP email is and see which SMTP port is the best one for our computers.

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What Is SMTP?

The communication protocol for email transmission is also referred to as Simple Mail Transfer Protocol (SMTP) in computer language. The SMTP port is akin to the person who sorts and delivers your email, or in other words, ‘the mailman inside your computers.’

SMTP is a protocol, a type of special networking software rule that allows your computers to link with other networks worldwide. Your IP address is also one such protocol. SMTP is vital to the grid because your emails cannot travel anywhere without SMTP.

We shall see how SMTP is crucial for emails before discussing the different types of SMTP ports.

SMTP Email – The Mailman

Understanding SMTP is essential to know how emails travel from one computer network to another.

This flowchart will explain it all. It is an ideal SMTP example.

Mail User Agent –> Mail Submission/Transfer Agent –> Mail Exchanger –> Mail Delivery Agent –> Mail recipient

The email sender or the MUA submits the email message to the MSA using the SMTP port. The MSA transfers it to the MTA (usually on the same machine or network), which then handles the Domain Name Server (DNS) to search in the MX records for the recipient’s domain. The MTA connects to the exchange server (MX) as an SMTP client. The MX hands the email message over to the MDA for forwarding it to the ultimate recipient. The end-user applications retrieve the emails using a different protocol known as Internet Message Access Protocol (IMAP).

Thus, you can see that SMTP represents the transporting aspect of the email. It does not have anything to do with the contents of the message.

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Different Types Of SMTP Ports

You might have heard these names before, SMTP Port 25, 465, 587, and others. Which of these SMTP ports is the ideal one for your emails? Let us have a look at these in brief

SMTP Port 25

This port has been the default transmission channel for transmitting emails between two servers since 1982. Even after more than three and a half decades, Port 25 has utility as the primary means of sending emails. However, many SMTP clients do not use Port 25 nowadays because of threats like spam. Most of the ISPs and hosting providers restrict or even block SMTP connections on Port 25. It reduces the chances of receiving unsolicited emails.

SMTP Port 465

This port is not much in use because most of the ESPs do not accept connections on the SMTP Port 465. It was never an official transmission channel but was used for SMTPS encryption and authentication. The purpose of introducing this port was to send emails securely over SSL. Today, STARTTLS has replaced SMTP Port 465, but some service providers still maintain it as the older MS applications do not support STARTTLS. (Note that SMTP Port 465 is no longer an accepted standard for SMTP)

SMTP Port 587

This port came into existence because of the submission of RFC 2476 to enable the introduction of the concept of splitting the conventional message submission and its relay. This port ensures that the security requirements do not interfere with the relay traffic over the message relay SMTP port 25. Almost all SMTP servers use this port as the default port today.

As we discuss the various SMTP ports, we should be aware of the concept of the SMTP server, as well.

What Is An SMTP Server?

The job of the SMTP servers is similar to other servers in many ways. Like all other servers, SMTP servers process data, but it has a specific purpose, and this is processing data related to sending, storing, relaying, and receiving of emails.

The SMTP server has an address and is generally formatted as smtp.serveraddress.com. A popular smtp server example is smtp.gmail.com. The role of the SMTP server is to process your emails and decide which server to send the mail to. We have explained this activity in detail earlier in the article when discussing the flowchart of the concept of SMTP email.

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Paid SMTP Server Or SMTP Server Free – Which Is Preferable?

The primary responsibility of the SMTP server is to ensure that your emails reach the end user’s inbox and not the spam or junk mail folders. There are both paid SMTP servers and free SMTP servers. Google or Outlook are some of the best examples of free SMTP servers.

They are useful but have their drawbacks. One such disadvantage is the limitation on the number of emails you can send. Therefore, the paid servers are beneficial to business entities, and domestic users can use the SMTP free servers.

What Is My SMTP Server?

Now that we have seen and understood the concept of SMTP email, it is natural for you to ask what is my SMTP server is. Here are some simple procedures for determining your SMTP server.

  • Internet Explorer –> Tools –> Internet options –> Programs –> Note the name of the email program. Check out the website of the email manufacture to know how to find the SMTP server.
  • Start –> Run –> Type CMD to open a DOS window. Type ping.smtp.mysite.com. On receiving the response, note the name of the server.
  • Tools –> Accounts –> Mail –> Default account –> Properties –> Choose server tab –> select outgoing mail to get the name of your SMTP server.
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Final Words

We have discussed the concept and importance of SMTP ports and servers. One should understand why it is called ‘simple’. It is because SMTP email can transfer only text. It cannot handle fonts, attachments, and graphics. Therefore, you have the concept of MIME (Multipurpose Internet Mail Extensions) for encoding all non-text content into plain text. Thus, SMTP becomes capable of transferring data efficiently. It is indeed the mailman inside our computers.

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