I want to know any suitable idea for getting the backup for Gmail accounts. I have 3-4 Gmail accounts and want to close 2 Gmail account. Having too many emails and other kinds of attachments their so, I'm unable to get back up from there. If anyone has the solution of getting backup of Gmail accounts.

Here is the solution to your problem. You can try the Gmail Backup without any doubt. The software is easy to use and light in weight that can easy to install and never make your computer slow. The software can easily provide a database of unlimited and big size files at the same time, without any data loss and without making duplicate files.
Visit here:- https://www.softwarewiki.org/backup-gmail/

Consider using the CloudMigration Gmail Backup Tool to backup your entire Gmail. It can save Gmail emails, calendars, contacts, drives, photos, and other Google data in various file formats. This tool provides you with advanced features that help you to create backups according to your requirements. Apart from this, it migrates Gmail emails to Office 365, Yahoo Mail, Thunderbird, AOL, etc. With its simple interface, you can backup Gmail without any technical knowledge. Moreover, you can also transfer emails from one Gmail account to another.