If you ever receive a bounced email or a notification saying “Disk Quota Exceeded”, you will need to change the mailbox quota for the email account in question, as you received the notification because the mailbox is currently full.
To do this, access the HestiaCP control panel and click the Mail (1) tab, then "Cuentas de correo" for the domain you want to modify:
Once there, select the email account you want to modify. In the "Cuota" section, select the desired mailbox size or choose the default size set for the domain. Select Aceptar. This will apply the changes. It’s that easy! 🙂