Email: POP or IMAP?

Email: POP or IMAP?

Email is arguably synonymous with the Internet, perhaps it was even your first interaction with digital communication? Email remains one of the most important aspects of modern business communication. If you are a business owner, employee, content-creator or even simply a consumer of the Internet — it is likely that email is now fundamental in your life and work.

In today’s hyper-connected world, where many of us access our emails from more than one location (often using more than one address), it is now more important than ever that we understand and make choices regarding which method we use to connect and access our emails.

Although many email hosts provide their own browser-based methods for accessing your mail (such as Google or Yahoo), many accounts can only be accessed through an email client application on your device. No matter which software or operating system you use, there are two methods for accessing your mail — POP or IMAP.

Email is sent from one address to another (or to many others in the case of group mails, CC or BCCs). When email is received, your server keeps ahold of it until it is told to delete it, either by yourself or by your email client. Most servers have a limited storage space for email. If you receive a lot of email containing large attachments, graphics or HTML code, your storage will be used faster than if you were to receive just plain-text communications. How this storage space is made use of and how your email is stored is dependent on whether you access your emails using POP or IMAP.

POP

The Post Office Protocol (POP) is most commonly used under its third revision (POP3). Created in 1984, POP is often considered the ‘default’ method for accessing your emails. This is a simplification of the POP process, but your email is accessed as such by your email client:

  1. Connect to the server using the login and password you provide.
  2. Check if there is new mail not previously downloaded to your device.
  3. Download a copy of your new emails to the Inbox on your computer.
  4. Send any mails in your outbox
  5. Delete old emails from the server (in-line with your deletion settings).

Your email client will allow you to specify after how long emails should be deleted from the server. Typically, POP keeps emails on the server to ensure that you have enough time to download a copy of it to your device (the default in Microsoft Outlook for example is 30 days). If you have multiple devices accessing the same email account, each device will get a copy of the emails on your server whilst it is still available. Emails can no longer be downloaded to new devices when they have been deleted from the server, so the deletion period is important to consider when using POP.

IMAP

An acronym of ‘Internet Message access protocol’, IMAP was created as an alternative to POP in 1986 and has seen many revisions since. With some providers like Google Mail actually requiring that you opt-in and agree to using IMAP for email, it is considered by some to be secondary in use to the POP method. So how does it differ? IMAP is a two-way protocol, which seeks to provide further functionality for the user. By always being connected to the mail server, your emails are constantly kept up to date and synchronised across all devices accessing your email using IMAP.

Similarly to POP, IMAP connects to the server to check for new mail, but where it differs is that it doesn’t always download your mail to your computer. Instead, IMAP tells your email client to download ‘headers’, effectively the most important metadata about your mail: the subject line, who sent it and where it was going. Only when you click onto an email does your computer download the information. Unlike POP, IMAP places priority on the server for storing your mail, rather than your device. This means that if you place email into a different folder, mark certain emails as read and delete others, the same changes will be reflected onto the server and therefore, across all of your devices.

Which method should I use?

Both POP and IMAP connect to your server where your email is stored, what your email client does next is dependent on which method you use to access your mail.

POP is simple, it downloads a copy of your email to your device and then either deletes that mail from the server or leaves it there for later deletion — it’s then up to you to ensure you have properly maintained back ups of your mail. By creating a local copy on your device, POP also ensures that you have copies of your emails when you cannot access the Internet. If you access your email on more than one device and then move email to a different folder or mark emails as read — the changes won’t be reflected across devices and you will have to make those changes multiple times. However, POP also puts preference on your device’s storage rather than the server. Mail can be removed from your server regularly, meaning that your server storage will never be clogged up by large attachments or years old email. POP can also be beneficial for those with email of a sensitive nature. In the Post-Snowden world, leaving digital traces, particularly for those involved in journalism or political dissidents, isn’t always desired — POP ensures that your mail is never left to linger in the cloud.

IMAP on the other hand always reflects your changes across devices. If you create an organisational, folder-based system to file away and archive your mail, it will be the same across all of your email-capable devices (handy if you use a mobile phone, tablet and computer to access your mail). Not only does it synchronise your inboxes, but it also keeps your Sent items, Drafts and Trash folders up to date, so you are always able to check what mails you have already sent, or continue writing your drafts from another device. However, by always storing your mail on the server, using IMAP can eventually clog your storage space if you don’t regularly delete your mail. The ‘constantly-connected’ nature of IMAP may not always be beneficial for those who have sporadic or temporary Internet connections. If you only have sporadic access to the Internet, POP may suit you better.

Even when there are now many startups that claim to have replaced email with their new service or network (see the countless instant messaging platforms that continue to launch on mobile, Slack or Skype), email remains firmly entrenched as the most dependent and widely-accepted of digital communication platforms. There are positives and negatives to each connection method, so choosing the right method for you and your work is an important decision to make. POP might best suit those who access mail from one device, have concerns over privacy and are on confident in their backup method. IMAP is better suited for users with readily available Internet access who read and write their emails from multiple places and devices, or who require the luxury of always being able to look through past communications with ease.

Are you looking to make the change from using POP to IMAP or vice versa to access your emails? The solution depends on which operating system, device and software you are using to access your mail. Get in touch by email, Twitter or leave a comment below and I would be happy to help you with the transition.