Microsoft Outlook is an application that is used mainly to send and receive emails. It can also be used to manage various types of personal data including calendar appointments and similar entries, tasks, contacts, and notes. 

Understand the difference between POP3 and IMAP 

IMAP is short for Internet Message Access Protocol, while POP translates to Post Office Protocol. In other words, both are email protocols. The main difference of the two protocols is that POP downloads emails from the server for permanent local storage, while IMAP leaves them on the server and just caches (temporarily stores) emails locally. In other words, IMAP is a form of cloud storage.

POP follows the simplistic idea that only one client requires access to mail on the server and that mails are best stored locally. IMAP was created to allow remote access to emails stored on a remote server. The idea was to allow multiple clients or users to manage the same inbox. So whether you log in from your home or your work computer, you will always see the same emails and folder structure since they are stored on the server and all changes you make to local copies are immediately synced to the server.

Comparison of POP3 and IMAP 

Characteristic POP3 IMAP
Basic Workflow 
  • Connect to server
  • Retrieve all email
  • Store locally as new mail
  • Delete mail from server (most POP clients provide an option to leave a copy of downloaded mail on the server) 
  • Disconnect 
  • Connect to server 
  • Fetch user requested content and cache it locally e.g. list of new mail, message summaries, or content of explicitly selected emails. 
  • Process user edits e.g. marking email as read, deleting emails, etc.
  • Disconnect   
  • Mail stored locally, i.e. always accessible, even without internet connection.
  • Internet connection needed only for sending and receiving mail.
  • Saves server storage space.
  • Option to leave copy of mail on server.
  • Consolidate multiple email accounts and servers into one inbox.
  • Mail stored on remote server, i.e. accessible from multiple different locations.
  • Internet connection needed to access mail.
  • Faster overview as only headers are downloaded until content is explicitly requested.
  • Mail is automatically backed up if server is managed properly.
  • Saves local storage space.
  • Option to store mail locally.

What is a suitable protocol for me?

Obviously, it depends on your specific variables and you probably have an idea of what is best suited for your situation already. The points below should help to make a final decision.

Choose POP if ....

  • You want to access your mail from only one single device.
  • You need constant access to your email, regardless of internet availability.
  • Your local storage space is limited.

Choose IMAP if ....

  • You want to access your email from multiple different devices.
  • You have a reliable and constant internet connection.
  • You want to receive a quick overview of new emails or emails on the server.
  • You have limited server storage.
  • You are worried about backing your emails up