This is how you can create Gmail filters:
If the idea of having to regularly clean Gmail inbox doesn't sound too appealing to you, we recommend you learn how to filter emails in Gmail to automate certain time-consuming email management tasks. Those who receive many emails on a daily basis need to clean Gmail inbox regularly to prevent them from piling on and gradually becoming unmanageable. You should also be safe to delete all emails that are older than 1 year, but caution is advised. A good rule of thumb is to delete all emails that are older than five years without opening them first.
Instead of a full date, you can also just specify the year. This search option tells Gmail to find all emails that were sent or received before the specified date and display them.
However, professional spammers will keep sending you unsolicited emails even after clicking the unsubscribe link or unsubscribing using Clean Email’s Gmail Unsubscriber. Otherwise, you can Pause some subscriptions to stop receiving emails from them until they are necessary again. That’s how easy it is to unsubscribe from unwanted marketing newsletters using Clean Email’s Gmail Unsubscriber.
Because those 15 gigabytes of storage space that all users get to enjoy for free are shared across all Google services, including Google Drive and Google Photos, a Gmail inbox can reach its capacity quicker than it might seem at first. With so much free space, it’s no wonder that Gmail users sometimes neglect inbox management, never deleting old emails, and seldom unsubscribing from newsletters they are no longer interested in.