Here is a step-by-step process for increasing your email storage space:

1. Investigate if an upgrade is available with your existing email provider.
2. Check with the email provider what the charge will be for email storage upgrades.
3. Switch to a free or low-cost email service that offers more storage space than your existing one.
4. Purchase an external hard drive and store emails on there.
5. Delete unwanted or large emails from the account.