The problem with web-based emails is that if you wanted to check your emails, you would need an internet connection. This shouldn’t be an issue if you’re at work or at home or in school, but what if you’re on the go and traveling and there’s no good/reliable internet connection? We suppose that might be that for some, but not for Gmail.
It seems that Google has started to roll out an offline mode for Gmail on the web. What this means is that Gmail users will be able to read and respond to emails even when offline. Now obviously responses made when offline means that they won’t and can’t be sent, but they will once a connection has been made.
That being said, users who wish to take advantage of this offline mode will require Google Chrome 61 or higher. They will also need to go into their Settings and choose how many days worth of messages that they want to keep offline. If there are messages older than the specified date, then you will not be able to access them.