Difference Between SMTP and FTP

Photo of author

By Sina Nasiri

Your browser and website servers use certain protocols and networks to provide you with the information you are looking for on the internet. There are 3 main file transfer protocols to move files over the internet. These are HTTP, SMTP, and FTP. Each of them has a unique method of transferring information.

HTTP is a well-known protocol as its initials can also be seen in the search bar. It stands for HyperText Transfer Protocol. The other 2 are not so well known but are equally important when it comes to transferring files. SMTP stands for Simple Mail Transfer Protocol and FTP is File Transfer Protocol.

Today, we will be learning the main differences between SMTP and FTP. Also, we will be answering the question if we can use the 2 interchangeably or not. Let’s start with FTP.

What is FTP (File Transfer Protocol)

As we have said, FTP stands for File Transfer Protocol, which is used by computers to send files over the internet. A user who receives the files will be given a different set of permissions like opening up the file, editing it, sending it back, or forwarding it. All these permissions are decided from the sender’s end and can be changed depending on their requirement.

For web developers, FTP is crucial as it is used to update the content on the website. Websites require a large number of files to transfer at high speed. As a result, FTP is the most secure and fastest way to deliver bulky files over the internet.

For FTP to work correctly, it needs to have an establishment in the connection and the communicator. To create these 2 parties, users need to have permission by providing credentials to the FTP server.

The FTP is both sent and received via port 21, and the transfer of files occurs under the guidance of the TCP protocol. Also, the transfer of files is asynchronous, which means the transfer of files takes place from one system to the other in one direction at any given time. As a result, it is much faster than the rest of the protocols.

The Objectives of FTP

There are 4 main objectives that FTP covers in its processing:

  • First, it is developed to make the transfer of files easier between the computers.
  • Also, with the use of FTP, the user can control their computer remotely.
  • To keep the files and how the data is being stored in the same variations.
  • Lastly, to transfer the data over the internet reliably and efficiently.

FTP is mainly designed in such a way that an individual needs to have software to use it properly.

Why Do You Need to Use the FTP Server?

As we already know, FTP mainly performs the transfer of files over the internet. For example, if you have many photos from the last vacation with your friends and they are asking you to share those photos, you can use the FTP transfer methods to transfer the same from the hosting server directly.

Asking yourself if you need an FTP server for yourself is a good question. Suppose you are the person who needs to send files to different people day in and day out then having your server is a great way to transfer files in a short time securely.

An FTP server also provides you space to properly organize all the files that you have in one place. In addition to this, it gives other users access to download files from the FTP server after your permission. Also, you can download files remotely anytime you want by providing the password.

The FTP server doesn’t restrict you when it comes to the file size unless you have specified it beforehand. Best of all, every file will be backed up and protected against several issues that could lead to the deletion of data. Many Youtubers have their FTP server to store all the videos they create. You can create an FTP server in your home if you have the technical expertise.

Working of FTP

Both the FTP client and FTP server work together to perform the file transfer operation as FTP works on a client-server model. A user configures the FTP server in the present network, and a specific file location is then located.

So it can be used as shared storage. Users can copy all the files that they want to share to this location. Once copying the files is done, the user will give access to the end-user to access all the files present in the FTP server.

The FTP client becomes the communicator agent, and it interacts with the server. In order to download and upload the files, the FTP client sends out the connection in simple words, which is then received by the FTP server.

After receiving the message from the client, FTP checks the request and allows uploading or downloading the file. Hence, the operation of transferring files takes place. Given below is the breakdown of this whole process and the different layers used in the FTP connection:

  • Control Connections

The control connections are usually placed on port 21, and it is the primary connection that performs the transfer of the files back and forth between the server and the user.

  • Data Connections

Now the connections have been established on port 21. The client and the server will form a separate data connection stream, which is solely created to transfer the files.

The data connection is kept open till the transfer of files is finished. Also, the data connection has to be closed by either a client or by the server, depending on which of the two are sending files in the first place.

  • Communication

    • Active mode

The active mode is used to connect from a random port on the FTP client to port 21 of the server. Also, this mode sends the PORT command, which provides the server information about the client’s port and from whom to make a connection.

    • Passive mode

The passive mode is used when the client is not able to accept the connection coming from the server end. In modern times this has become the most used mode of transferring data. Because clients are always behind the firewall these days, in this case, a connection is made from the user end to a random port on the FTP client to port 21 of the server.

After that, the server sends a PASV command that lets the client know which port to connect to. The client connects to the random port which the server has assigned it, and the transfer of file takes place.

  • Command Processing

Command processing is the method that is used by the client’s side computer during the connection process. Once the connection is successful, the server uses the same path to send the command’s response back to the client.

Advantages of Using FTP

There are other options for sending files. But some of the compelling reasons to transfer files via FTP are:

  • Security – The most significant benefit of using the FTP server to send files is the different levels of security it provides. Also, users can choose which security option they like the most and select it for the file transfer.
  • Control – Another great benefit is that you have proper control over your data transfer. Even the granules of control are given to you. So you can determine who can upload, download, edit, and share the files.
    Not everyone in your company needs to have the same level of administrative power over the server, and FTP gives you the ability to manage it more efficiently.
  • Bigger File Transfers – With FTP servers, your problem of sending bigger files to the recipient will vanish in the air. With a dedicated FTP server, you can send gigabytes of data in seconds by setting it up with a 10-gigabit network connection.
  • Disaster Recovery – If any system goes down in your company, their data can be retrieved by the FTP server. It will make sure that none of your files gets corrupted due to the system failure.

Disadvantages of Using FTP

Important disadvantages of using FTP are:

  • Packet Capture Issue – First, FTP servers don’t have their own encryption system. As a result, a hacker can easily intercept the data flow and read out all the information without having to find any public or private keys.
  • Not All Vendors Are Same – If you choose the wrong vendor, your data can go under attack. You could find yourself stuck with the FTP solution, which leaves your data vulnerable at times.
    As a result, it’s a pretty tough job to find the right vendor for your FTP server. Yes, you can make one by yourself, but that’s another tedious task that requires lots of technical expertise.

What is SMTP?

The world of SMTP is complicated, and if you are a newbie, you are surely going to get overwhelmed. But let’s try to make things easy for you. An SMTP server stands for Simple Mail Transfer Protocol.

The primary purpose of the SMTP server is to send, receive and forward the emails between the sender and the receiver. The SMTP server has an address that can be set by the mail client or application the user has. One of the common examples of an SMTP server is the Gmail server address.

The SMTP server is not quite like a standard server, but an SMTP server doesn’t have to be necessarily on a machine. It’s more of an application that is constantly running in order to send and receive mail.

The Objective Of SMTP

Its main objective is to send email messages via servers. The process can be broken down into 3 steps, which are:

  1. First, you have a mail client which uses the SMTP method to send a message to the mail server.
  2. The mail server receives the transmission and sends it to the destination server by using the SMTP server.
  3. The client who is at the destination uses POP or IMAP to retrieve the message that the server has sent.

Why Do We Need SMTP?

SMTP is the short form of Simple Mail Transfer Protocol, and SMTP is the set of communication guidelines that are used over the internet to send and deliver emails. An email, if we look at it, is just a string of text. SMTP helps both the server and the user to prioritize the emails as most of the critical information is sent via email.

Now to the main question: why do we need SMTP? SMTP is like an express lane present on the internet, so the transfer of emails doesn’t have to wait for any delay. As a result, emails are still considered the best medium to send and receive important information in a short time.

The email transfers are almost instant. Moreover, an SMTP server is also responsible for setting up communication between servers. The first server will conjure all the information it has and present the operations it will perform.

The email is sent from the receiving end only if it recognizes the operations sent by the first server. SMTP is only used for sending text messages. Suppose you are thinking about transferring photos and videos, then it would help if you looked for FTP as it is more secure and fast.

Working of SMTP

In the SMTP models, the user gets to deal with the user agent (UA) such as Microsoft Outlook, Gmail, Yahoo Mail, and Mozilla. MTA is also used during the exchange of mail, which is using the TCP. In no way, the user gets to interact with the message transfer agent. It is the responsibility of the administration to set up the local MTA.

In MTA, there is a small queue of mails, so in case the receiving end is not able to receive the mail on the first try. It can schedule a repeat delivery. MTA is responsible for mailing the emails to the receiver’s mail. Later, the information present in the mail can be downloaded.

There are 3 significant SMTP parts that work together to send your mail:

  • Composition of Mail

First, you write the mail, and it is sent by a series of requests and responses from the server. The message which is sent to the server has two parts, the header, and the body. A null line is used to define the ending of the header.

Everything present after the null is considered to be the message body. It uses the sequence of ASCII characters. All the information that you want to send via email is present in the body.

  • Submission of Mail

Once you have written the mail, the email client that submits the completed mail as one to the SMTP server by using the protocol SMTP on TCP port 25.

  • Delivery of Mail

There are two parts of an email address, the username, and the domain name, for example, somebody@gmail.com. Here somebody is the username of the person, and gmail.com is the domain name. If the mail sender and the receiver have different domains, then the sender’s MSA will send the mail to the Mail Transfer Agent.

The MTA will relay the email and find the MTA of the target domain. It checks the MX record from the Domain Name System to obtain the targeted domain. Once the domain and the name required of the user are located, MTA makes the connection and exchanges the server to relay the message.

Different Types of SMTP Transfers

There are 2 methods that are used by SMTP for sending and receiving mail. These are end-to-end and store-and-forward:

  • End-to-end

In this transfer process, the client’s SMTP server will initiate the communication session. On the other hand, the SMTP at the receiver’s end will respond to the client’s request. This mode of transfer is used to send emails to servers at various organizations. This model became the preferred mode of communication between multiple organizations and domains.

  • Store-and-forward

This mail transfer is only used when the sender and the receiver are both from the same organization after setting up the communication by the receiver’s SMTP. The SMTP server will make a copy of the mail and store it in itself until the receiver’s SMTP has received the copy of the mail successfully.

Advantages of Using SMTP

  • Easy To Use

It is one of the fastest ways to send and receive text messages on the internet. It can be used on a number of systems, networks, and even tools. Even the most basic computer is able to send an email across the world using the internet.

  • Long Reach

As we said, you can send the mail sitting anywhere in the world, and in an instant, it will be delivered to the receiver. The SMTP protocol is specifically designed to send only text messages on the internet. As a result, it gets a priority transfer when you send a mail.

  • Connect With Any System

Emails are now a part of our daily life. If you are working in a company, you know how important it is to keep an eye on your emails. Now emails can be sent from any smartphone, and you don’t need to have a computer or a laptop near you to send them.

Even a first-generation smartphone was capable of sending mail. This shows how flexible the SMTP connection is. It really has no restrictions when it comes to compatibility.

  • No Need of Development

SMTP is already a well-developed and distributed protocol. There is no additional development required from your end to use this transfer protocol.

Head to Head Comparison between SMTP vs FTP

So there you have it, these are the main differences between SMTP vs. FTP. Each of these protocols has its own benefits and disadvantages as well. When you are using the internet to send files to someone, you might be using one of these or both of them at the same time. Given below is the side-by-side comparison between SMTP and FTP.

SMTP uses port number 25 FTP uses 20 and 21 port numbers
The SMTP connection uses In-band transfer protocols. FTP uses Out-Of-band transfer protocols
It does not have any state, and with the requirement, SMTP makes changes in itself. During the transfer of the emails, FTP maintains its state.
There is only one TCP connection present in SMTP, and it is a persistent connection. There are two TCP connections present in the FTP, the first one is for data connection, and the second one is used as a control connection.
The transfer protocols mainly work on the push protocol system. The TCP connection of FTP is persistent for the control connection, and if TCP is using a data connection, then the FTP protocol becomes non-persistent.
Lastly, the transfer of mails between the two users takes place via servers. The transfer of mails takes place directly between two computers.


But when it comes to using them in the place of the other, that’s where both the FTP and SMTP fail. SMTP can only be used to send emails that are text-based while FTP is only used for sending files and no text messages. Thus, you can’t use them interchangeably as both protocols will not function properly, and you will have an error code.

People are also reading:

Leave a Comment