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 Accounts under the "Email > Email Accounts" tab
3) Look for the email you want to change the quota for
4) Then specify the selected Email Account -> manage
5) After that, adjust the quota you want, if so, click "update email settings"