The question seems fairly straightforward, why use Gmail over any POP email services? The best place to start is to differentiate between the different emails protocols, or how we receive, store and access our messages.
Email Protocols
Internet Message Access Protocol, or commonly known as IMAP is protocol that allows an email client (Such as Outlook or Mail through Apple) to access your email on a remote mail server.This method supports both on-line and off-line modes of operation. IMAP generally leaves messages on a server, meaning that as long as you know your username and password (As well as an active internet connection or Data from a mobile provider) you can access email on almost any device from anywhere.
Post Office Protocol, or commonly known as POP is a protocol that sends your email without ever being stored on a server. The email you send leaves your machine and shows up in someone else’s inbox. The email then lives on your device (Phone, tablet, PC, etc.) and nowhere else. The biggest downfall to POP email is that if you lose your phone, or your computer crashes, your email messages are lost forever. Additionally, due to how email is stored on a device, you cannot access previous emails from a different device, and your email must be stored on the device you are using.
IMAP Benefits
From a business perspective, it makes sense that you will want to access your email regardless of where you are at, and which device you are using. There are email services that exist that allow you to switch between POP and IMAP protocols, in case a circumstance exists in which you would find a benefit to have them stored on your device. IMAP generally only saves titles, and a hand full of email on your device at a time. Meaning that you will need to login to view your email, and access the server on which they are stored. So while there may be some benefits to storing email on your device, and having the ability to view them in their entirety when you have no access to internet, this is not a common problem for business in today’s environment. Gmail is a great example of a service, both business level subscriptions and their standard free version offer the flexibility to switch between protocols, allowing you to utilize the benefits of both.
Additionally, because users are increasingly more mobile, IMAP services allows you to sync your calendars and contacts to multiple devices, allowing you to not only have access to your emails, but also your schedules and important contacts while you are away from your desk.
Resources:
Internet Message Access Protocol
Google Support for IMAP and POP Settings