One Gmail account can be used as eight

        Generally speaking, you can only apply for one free email account at a time. If you need more, you have to apply for another one. But in this way, you will need to manage multiple email accounts and remember multiple accounts, which is especially inconvenient for users who use browsers to check emails, as they need to log in and out multiple times.

        Gmail can solve this problem well:　　Assume you have four different types of contacts: manuscript authors, girlfriend, classmates, and colleagues. You don't want their emails mixed together. You don't need to apply for 4 email accounts (Gmail currently cannot be applied for casually, it requires an invitation), you just need to apply for one email account, for example, [email protected]. Then add a "+" and a name before the "@" to form a new email address, such as [email protected], [email protected], [email protected]... Tell these new email addresses to different people and let them send emails.

        Originally, Gmail ignores the part after the "+" in the username, so actually these emails will still be sent to [email protected].

        In "Settings → Labels", add labels for these different groups of people for classification. In "Settings → Filters", add a filter with the condition that the recipient is [email protected]. Click "Next Step", select the label created in the previous step - "Manuscripts", and then complete the settings.

        After setting up the other three types of contacts in the same way, you can click on the labels on the left side to view related emails without any confusion.