Pop can be used to ready your emails of gmails in other email clients but it can be only used on a single computer these steps helps you to set up pop in Gmail
:-Launch Gmail on your device
:-and then click on settings
:-click on the tab forwarding and POP/IMAP
:-Enable pop for all emails or Enable pop for mail that arrives
These steps help you to set up pop in Gmail
read for more information:-https://getassist.net/why-is-gmail-not-syncing-how-to-fix/