Depending on your needs and situation, you may need to increase or decrease your email quota.
Increasing the email quota will allow users to store more emails before deleting mail or emptying the junk mail folder.
1) Login to cPanel by accessing the URL http: // domainname / cpanel /
2) Click on Email Account under the "Mail" tab
3) Search for the Email that you want to change the quota
4) Then specify the selected Email Account -> Change Quota and specify the amount you want to change and click Change Quota