POP and IMAP are the two most widely used email protocols on the Internet. Both enable a client to communicate with email servers, but in very different ways.
How Does POP Work?
POP (Post Office Protocol) is the older of the two protocols used for accessing email. The simplest way to describe how it works is that it retrieves messages stored on the mail server and downloads them to the email client. If you are using POP and try to access your email from a different client than the default, or from webmail, the messages will be deleted from the server. Although some clients offer a feature to keep a copy of the emails on the server, IMAP is usually the preferable option if it’s available. However, POP has its advantages. Emails are accessible even without an internet connection, making it ideal for those who need offline access to their emails at all times.
How Does IMAP Work?
IMAP is the most popular method for connecting to an email server. IMAP simply displays the contents of your mailbox exactly as they appear on the server. IMAP synchronises the client with the mail server, so only copies of your emails are downloaded to the client. Spam folders can only be accessed by using the IMAP protocol by default, so an IMAP connection is required to view and delete messages. Webmail also uses IMAP. It is highly recommended that you use IMAP, as it allows you to keep track of your spam folder, and you can access your emails from anywhere since they have not been downloaded from the server.