When you use email with a web-browser, you basically use a web-based interface of Gmail client to retrieve messages from Gmail servers themselves, associated with your account. But when you use other email clients, like Outlook, Thunderbird, Apple Mail, or any other, these clients must “contact” your Gmail servers to retrieve those messages and allow you to make changes.
IMAP Vs Other Protocols
This action of email clients connecting with the mail servers and retrieving the data is why we need IMAP or POP and other such protocols. These protocols define how the data is accessed and how the changes are made locally and on the servers.
POP was an older internet protocol used by email clients and emailing services. It’s still in use but not as much as IMAP. And there are many reasons for that.
In simple terms, POP is mostly a one-way communication method between servers and clients. Clients can access emails using POP and download them locally on your computer, and you have the option to delete those messages from the servers if you want. Later extension of POP also allows users to download only email headers and download content only for specific emails. This was usually done for saving space on the computer, as full messages can take up disk space. But there is no communication back to the servers.
So, straightway, there are some obvious flaws with POP compared to how you must be used to receiving your emails today. POP makes you limited to one specific computer where the client is installed. You cannot make changes to emails or folders and then see those changes reflect back on the servers.
To solve this issue and many others that POP had, we have IMAP, the most used internet standard protocol that almost email clients and emailing services use. You can check if your email provider allows IMAP and if it is turned on or not by going into server settings.
IMAP (Internet Message Access Protocol)
IMAP stands for ‘Internet Message Access Protocol’ and it was originally developed way back before the 90s, but didn’t come into full effect much later. Today, it’s the most used protocol used.
It was designed to manage the entire emailing needs of users through an email client. Unlike POP, IMAP protocol retrieves mails from the servers and any changes made on the client gets synchronized back to the servers. This allows users to access the same managed content from their computer and as well as from any where using the web client after signing in and be able to see the same database.
You can not only download emails from the servers and locally to your computer, but you can also delete, modify them, or create new mailbox folders, and many more actions. All of this gets synchronized between client on the desktop and the mail servers.
Here are some more advantages of IMAP over previous protocols like POP:
- Since POP connects to the internet only to download the emails, you are not always in an online mode. But with IMAP, you can always remain connected, which helps in faster response times.
- You can only use one client when using POP, but can use any number of clients on any number of computers when connected using IMAP. For instance, you can use Outlook at home and Thunderbird at Office to access the same email account and same messages and work seamlessly across both of them without worrying about seeing any conflicts or missing information, given the data was fully synchronized.
- IMAP allows users to see emails statuses like read, replied to, moved, or deleted. But with POP, if you have read an email after it was downloaded to computer, the email on the server will still be ‘unread.’ Such flag statues and metadata are also in sync when using IMAP.
- Email clients also offer searches from the servers, in case, the search didn’t show any result from the locally downloaded files. Sometimes, users do not download all the emails (like from years ago is kept usually on the servers), but you can search those emails on servers from the email client if you are connected using IMAP.
- IMAP protocol has the feature that lets you download particular parts of a MIME define email. MIME is the most commonly used format for emails, which makes it possible for them to have a tree or hierarchy structure. With IMAP, you can make use of MIME format, for example, fetch only the text of the emails, leaving behind the attachments. This gives users more control on how they want to manage their data and therefore, also space used by the data on the computer and on the servers.
The only disadvantage of IMAP is because of its sophistication and the fact that it can offer many features. This can sometimes bring extra load on the servers and the clients. IMAP also often consumes additional data usage and disk space on the computers due to its very nature of being always connected and syncing data in both directions.
But despite these flaws, without the IMAP protocol, it is virtually impossible to do many of the emailing operations that most of the modern-day users are used to.
Conclusion
On a final note, check with your emailing provider that they allow IMAP connections and that it is not turned off by default. For instance, in Gmail, you can go to the settings -> Forwarding and POP/IMAP -> and click on “Enable IMAP” if it is not already enabled. Here you can also tweak other IMAP related settings, such as, whether to immediately update the server or wait for the client to update it. Other email providers (like Outlook.com) also has similar options. By default, in most cases, IMAP is enabled and the emails downloaded by the client using IMAP are also kept on the servers (which you can change to “delete” if that serves your purposes).