What is Post Office Protocol 3( POP3)?

What is Post Office Protocol 3

The majority of users who heavily rely on email to manage their business or work will have used some client software such as Outlook to manage and deal with their email. Messages must be recovered using the post office protocol before the user can download the emails from the server.

Therefore, post office protocol 3 is essential if you are going to manage your emails with client software. Learn more about POP3 in this article. It will help you understand what POP3 is and how it works.

What is POP3?

The Post Office Protocol (POP3) is an Internet standard protocol utilised to retrieve or store emails or messages from SMTP hosts. The first version of Post Office Protocol was released in 1984. However, currently, it is running on the 3rd version of POP3 and has become a well-known protocol utilised in every email client to date. Prevalence is the simplicity of POP3, along with its ease of configuration, operation, and maintenance.

The ISP (Internet Service Provider) facilitated the email servers and also used POP3 to get and hold emails for their users. Occasionally, users tend to utilise the email client system to check their email boxes from a remote server. The emails are also downloadable from the server.

When the email client has downloaded the emails, the server usually removes them. However, a few of the email clients permit users to copy or save some of their emails on the server for some time.

TCP port 110 is mainly used by email clients to link with a POP3 server. However, users have the option to decide to connect by utilising the STLS command after utilising POP3S if the encrypted communication is supported on the POP3 server. Transport Layer Security (TLS) or Secure Sockets Layer (SSL) are two ways to connect the server on TCP port 995.

History of Post Office Protocol

The Internet Engineering Task Force launched the Post Office Protocol in 1984 after receiving comments from RFC 918. The developers of those days felt the need to develop a fast and simple method of recovering emails from a server. Developers perceived reading offline emails as more advantageous than getting access to the mailbox online.

After that, Post Office Protocol version 2 was launched in 1985 in RFC 937, which the POP3 later replaced in 1988 with the distribution of RFC 1081. There were various redesigns made to POP3 in the following ten years before it was finally set to the present specification as RFC 1939 in 1996.

Even though POP3 has undergone various improvements and refinements, the basic principles of a simple protocol with a three-stage process to retrieve mail were maintained between users and the server by the developers. The level of simplicity is the factor that makes POP3 perhaps the most famous mail retrieval technique utilised today..

How does the Post of Protocol Work?

Whenever a user browses for a new email, the client-server will link to the POP3 server. After that, the username and password of the user are delivered by an email client to the server for verification. Once it is connected, the client’s series of commands based on text messages is issued to recover all email messages. Therefore, the user’s local device or computer hard drive is used to store the downloaded email. Afterward, it erases the copies from the server and disconnects from the server.

As a matter of fact, after retrieving the server emails, they are erased. Consequently, the emails are attached to that specific machine, and it wouldn’t be imaginable to get similar emails from an email client on another device. An easy way to fix this issue is by customizing client email settings to generate a copy of the email on the server.

Whenever the email client searches for new emails, all the previous emails are downloaded and erased from the server to free up space on the pm mailbox server. The user’s computer is used to store the offline emails with an unlimited mailbox size. However, it depends upon the hard drive size of the computer or device. POP3 makes it a little challenging for users to export emails once they choose the email programme or computer.

The POP3 client creates a Transmission Control Protocol (TCP) session with TCP port 110 to retrieve the message. Then POP3 recognizes itself to the server and afterward gives a series of POP3 commands as below:

Stat: Request the server for the number of messages ready to be recovered

List: Check each message size to retrieve it

Retr: Retrieves individual messages

Stop: Ends the POP3 meeting

The application uses the Post office Protocol

With its streamlined process of stopping and receiving email, POP3 can be used with any email program that is arranged to support it. Most popular email programs, such as Outlook Express, support POP3.

Other than email programmes using POP3 to recover mail, the POP3 protocol is likewise utilised by the backup and synchronisation program, SyncBackPro, by 2BrightSparks Pte. Ltd.

To back up the stored email on the server, SyncBackPro is utilized. It additionally helps to prevent email backups on any POP3 and IMAP4 server. With the help of this method, any email backed up is simply downloaded and stored in its own independent EML record that contains the email body and all the attachments in it.

It is essential to keep in mind that SyncBackPro can’t restore copies of such supported emails to an email server-only the backup of local safekeeping is possible. This component is valuable for webmail users looking to backup files of their stored emails to avoid being affected by, for instance, the closure of the mail provider site, evacuation or corruption of email accounts, or other unanticipated disasters.

Advantages and Disadvantages of using POP3

While POP3 has undergone numerous improvements since it was introduced during the 1980s, its streamlined usability makes it a popular email system. Its uniqueness is also based on the fact that it is able to recover emails efficiently and with few errors. While several enhancements and changes have been made through the First Post Office Protocol to the current POP3, it still lacks a few features and has a few issues.

Let’s discuss both advantages and disadvantages of POP3.

Advantages of POP3

  • While utilising POP3, users have the option to download emails directly to their computers and can read the messages in offline mode too.
  • POP3 makes it relatively straightforward to open attachments as they are already downloaded.
  • It doesn’t demand much storage space; the user’s local device or hard drive is used to store all emails.
  • Despite the unlimited storage options, they could only be restricted based on the user’s hard drive space.
  • POP3 is relatively easy to set up, extremely famous, and reliable.

Disadvantages of POP3

  • Users don’t have the option to access emails from different machines yet; they first have to configure them to do so.
  • Users don’t get the option to transfer the mail folders to another email client or physical machine.
  • Users can also lose access to their entire data stored in emails if email folders get corrupted. There is no way to recover it again.
  • The attachments in the email could consist of malware or online viruses, which might compromise the user’s personal data stored on a computer if they are opened on it.

What is the relation between POP3, IMAP, and SMTP?

IMAP is an alternative email recovery protocol. In the same way as remote file servers, IMAP allows clients to hold email on the server while holding emails can also be organized into folders.

Similar to POP3, IMAP supports the latest email clients and web servers. Yet, unlike POP3, by synchronising the emails from multiple platforms or clients, IMAP makes it more appropriate than POP3 when a client is working with numerous devices or needs to get to an email from different locations. The working ports of IMAP are ports 143 and 993.

However, POP3 and IMAP relate to email receipt; they contrast with the Simple Mail Transfer Protocol (SMTP). SMTP is mainly a protocol for moving email online. Also, assist in sending email and receiving it by a primary handler for the beneficiaries. However, these emails are read with the help of POP3 or IMAP.

Final Thoughts

Despite being around since the 1980s, POP3 remains one of the most suitable and important email protocols. By stopping emails from being stored on users’ computers or devices, it permits users to access their email and messages offline without being constrained by the storage limit of the server. It would be prudent to be cautious when dealing with POP3, as attachments and emails may contain malware and viruses, which can severely compromise your security.


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