IMAP and POP3 Protocols Guide

Everyone with an email account will benefit from understanding IMAP and POP protocols. In simple terms, IMAP protocols and POP protocols ensure that messages are properly handled in your email account. IMAP protocols synchronize messages between devices; while POP downloads messages from the server to your email application. Whether you use your email account through webmail or an email client, it’s helpful to understand how IMAP and POP protocols work so you can fully understand the technical aspects of your email account.

Are you preparing to add your email account to eM Client or another email application? Knowing the basics of IMAP and POP3 protocols and how they work with SMTP and TCP protocols will help you determine what’s best for your email experience.

TCP Protocols

The TCP protocol meaning is Transmission Control Protocol. TCP protocols facilitate the sending of information through the internet. TCP protocols ensure that servers are able to send and receive information. TCP protocols allow other protocols, like IMAP, POP3, and SMTP, to connect to the network and send and receive messages.

IMAP Protocol

What does IMAP stand for?

The IMAP full form is Internet Message Access Protocol. The purpose of an IMAP protocol is to access stored messages from a mail server. An IMAP protocol is essentially what allows you to get your emails from your inbox to your device. IMAP protocols also enable the connection between your email account to a third-party email application on your device.

If you want to know what is an IMAP server; it’s the mail server previously referenced that supports connections through IMAP protocols. The IMAP server is the middleman between the sender and the device where you access your messages. This enables synchronization between the server and your device.

IMAP port SSL information

The port number for IMAP port SSL is 993. The IMAP port without SSL is port number 143.

IMAP port SSL 993 is recommended because it works with SSL encryption and will ensure that your emails remain secure. The alternative IMAP port number is 143. IMAP port number 143 does not include encryption and therefore it’s important to proceed with caution if you’re sending or receiving secure messages through IMAP port 143.

POP3 Protocol

What is the difference between POP3 and IMAP?

POP3 stands for Post Office Protocol 3. POP3 protocols download your messages to the correct location. The main major difference between POP3 and IMAP is that POP3 handles data differently.

POP3 accounts can technically be set up on multiple devices, but the information will not be synchronized like it is for IMAP accounts. POP3 might be your preferred choice if you do not have the space to handle storage on your mail server, and instead prefer to download your messages so they can be deleted on your mail server. Your messages can be set to download from an email application to your computer via POP3 protocols.

If you need to access your emails from a work computer, personal computer, or smartphone; you can still use POP3. However, in that case, it’s important that you do not set your downloaded messages to be deleted - this allows you to access your emails from another device.

What is the POP3 default port?

You have two options for the POP3 default port: port 110 and port 995.

The POP3 default port 110 does not provide encryption, so messages are not secured during the sending process. Anyone looking for additional security to protect their email correspondence should opt for the POP3 SSL port 995. POP3 SSL port 995 is encrypted and will protect your messages from being read by hackers.

SMTP Protocol

What are SMTP protocols?

The SMTP protocol full form name is Simple Mail Transfer Protocol. As the name suggests, the SMTP protocol is used simply to identify and communicate between email addresses. The SMTP protocol assists in the communication between the email addresses and ensures that the mail reaches the correct sender. SMTP protocols are used primarily by email clients for sending mail.

SMTP default port

It’s suggested to use the SMTP default port 587. Port 587 for SMTP protocols is encrypted. There are other port options for SMTP, but port 587 is currently the option that is most often used.

What is POP before SMTP?

POP before SMTP is a process that can be set up for your email client that enables other external users to send mail through your account. POP before SMTP is typically a temporary option. It can only be used by another user for a short duration of time for security purposes. POP before SMTP might be used in situations where another authorized user needs to access your account to send information to a recipient.

Use IMAP and POP3 protocols to add your account to eM Client

When you add your email account to eM Client, you’ve got a couple of options for account setup: automatic or manual. Users who select a manual setup in eM Client will need to know their POP3 or IMAP protocol information in order to add their account.

  • After clicking Menu > Accounts > Add Account, the following window will appear:
    eM Client: Chat easily inside your mail app
    eM Client: Chat easily inside your mail app

    Add account menu option (left) and the account setup window (right)

  • Select Mail > Other. After you add the name of your email account in the Identity page, the Incoming Server page will allow you to add your POP3 or IMAP protocol information.
    eM Client: Chat easily inside your mail app Incoming server page shown above
  • Add the name of your server for the Incoming and Outgoing server pages. The name of the server might include the domain or the name of the protocol. For example, if you use Gmail, you could add,, or If you are unsure about the name of your server, go to your mail provider’s website and check to see what you should use.
  • Once this process has been completed, the test configuration page will ensure that the IMAP or POP3 and SMTP protocols are effectively communicating between your email account’s mail server and eM Client.

For steps 5-7, you’ll add your basic account details, manage your encryption settings, and then finally complete the account setup process. If you’d like to view a detailed step-by-step guide for adding your email account to eM Client, check out our account setup article here.

Want to learn more about how to get the most out of your email account with eM Client? Check out our blog to learn new tips and tricks to become an email wizard.