How to change an email account's quota in Plesk
Now let's learn how to change an email account's quota
1. Click the "Mail" tab.
2. Click the email address you want to change the quota for.
3. When setting an account's quota, you can either choose the default size...
... or you can assign a custom quota.
4. When ready, click the "OK" button.
That's it! The quota has been changed for that account.