If you’re like most people, your email account is probably the centralized hub of your personal activity. All of your Facebook notifications, website registrations, newsletters, messages, etc. get sent to your email box, right? That means you’re putting all of your eggs in one basket – if that basket happens to fall, you’ll lose all your eggs with it.
In other words, if you bring all of your activity into a single email account, what happens when someone breaks into it? I’d say it’s plausible that they would gain access to everything else. This is why you should use multiple email accounts.
Having separate email accounts will not only help boost your security, but also your productivity. Imagine if you could consolidate all of your work emails into a single work account; all of your friends and family communicate with your personal account; you have a recreational account for various websites; and a throwaway account for potential spam links. This way, if someone hacks your work account, all of your personal emails are still safe. (reproduced from Makeuseof news)