This article covers checking the size of emails of a hosting service and of individual mailboxes. If you need to increase the capacity, follow the guide Email – Increasing Mailbox Storage.
In this article, you will read about:
- How to set the size of mailboxes
- How to check the usage of an email mailbox:
- Common problems
- Frequently Asked Questions
Mailbox size
By default, the size of individual mailboxes is unlimited, and their usage counts towards the total hosting space. The same applies to the maximum daily number of sent emails.
If you want to limit the size of individual mailboxes, follow these steps:
- Log in to Customer Administration ⧉.
- In the top menu, select Hosting services Webhosting, Mailhosting, Hosting WP, or WMS.
- Select from the list the service whose mailbox you want to check.
- In the left menu, click Mailboxes.
- In the table, open the detail of the mailbox you want to limit.
- In the Mailbox limits section, set the required size (to restore the default setting, delete the value).
- Click the Save Changes.
Open the list of the service’s mailboxes:

Checking mailbox usage
If the usage of your mailboxes reaches 90% or 98%, the system will notify you by email (unless you disable this setting). If you have limited the capacity of a specific mailbox in its settings, the system sends notifications to that mailbox automatically.
A completely full mailbox blocks both receiving and sending email. You can resolve an overfull mailbox by:
- Cleaning up – delete unneeded sent and received email, especially SPAM.
- Navýšením prostoru podle návodu Email – Increasing Mailbox Storage.
Checking in the Customer Administration
To check mailbox usage in the Customer Administration, follow these steps:
- Log in to Customer Administration ⧉.
- In the top menu, select Hosting services Webhosting, Mailhosting, WebSite, or WMS.
- Select from the list the service whose mailbox you want to check.
- In the left menu, click Mailboxes.
- In the table, check the size of the individual mailboxes and the total size as of the stated date and time.
Check the mailboxes of the service:

The system updates mailbox sizes in the Customer Administration at irregular intervals. You can find the dates and times for which the sizes are valid in the table right next to the size records.
Another way to find out the current size of emails in the Customer Administration is to run a diagnostic.
Checking in WebMail
To check mailbox usage in the WebMail client, follow these steps:
- Log in to WebMail ⧉.
- You can find the mailbox usage (as a percentage) at the bottom of the left menu.

Common problems
Common problems with checking mailbox usage include:
Outdated email size information
Problem: After deleting emails, the system still shows the old values.
Cause: The system does not update the recalculated values in the administration continuously. When an update does occur, however, it displays the time of the last update along with the value.
Solution: If you need the email size information updated as soon as possible, contact Support with a request to update the email quota. Include the name of the service.
Frequently Asked Questions
How do I find out which data fills a mailbox the most?
The easiest way to see the usage of individual mailboxes is in the administration.
You can see the usage of individual mailbox folders in WebMail ⧉ v Nastavení Folders (Selected folder) Velikost. Velikost jednotlivých e-mailů je uvedena v přehledu.