When an email account is created in cPanel, the email account quota is sometimes left on the default setting (often 100MB or 250MB). Your quota can quickly become full, even with a relatively quiet email address.
You can either set the quota option when creating email accounts or adjust it later should you be short on disk space.
No further emails to that email address will be delivered when an account exceeds its quota. A delivery failure notification will then be returned to the sender.
An example notification is as follows:
This message was created automatically by mail delivery software. A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed: [email protected] Mailbox quota exceeded
How to Increase your Email Quota in cPanel
This tutorial will show you how to increase your email quota in cPanel to the one of your choosing.
The first step is to access the email account administration area by clicking on the Email Accounts icon.
This is boxed red in the image under the Mail section of cPanel.
- After Step 1, you should have landed in the Email Accounts section of cPanel, with the “Email Accounts” tab active.
- Click the “Disk and Quota Link” next to your chosen email account to reveal the settings.
You will now see an option to change the Mailbox Quota.
You will have two options:
- Custom Mailbox size: You can enter a custom size in MB.
- Maximum Mailbox size: The second option will display the maximum mailbox size. This may be a limit set by your host, or simply say “unlimited.”
When choosing a Mailbox Quota, you will need to ensure that it is:
- Within your web hosting plan’s limitations.
- Within the maximum allowed quota. On 32-bit operating systems, the maximum permitted is 4096GB, and 4TB on 64-bit operating systems.
If your custom mailbox size does not comply with the above limits, you will see a red warning box appear.
The mailbox quota amount does not include emails located in your mailbox’s trash folder.
Once you are happy with your chosen settings, click the “Save” button to confirm the changes.
Mailbox Disk Quota Email Notifications
For shared hosting, many hosting providers will set a maximum mailbox size for your cPanel account.
If a limit is set for your cPanel account, you will likely receive email notifications when you near your mailbox quota. By default (your host may have altered the specific thresholds in the cPanel WebHost Manager (WHM)), the following warnings will be sent:
- Mailbox disk quota “warn” percentage - 80% Full
- Mailbox disk quota “critical” percentage - 90% Full
- Mailbox disk quota “full” percentage - 98% Full
If you receive a warning, you can take action. This may include increasing your mailbox quota or deleting old emails.
How many emails is 100mb?
This depends entirely on the content and size of the messages.
An email consists of a header and the message body, the latter of which includes encoded attachments.
Modern email programs such as Office 365 will add about 30kb of data in the header, including message authentication, spam scores, and sender metadata. Modern HTML email will add styling, layout markup, logos, and other information. HTML emails often are sent with a duplicate plain text version too. This can inflate the size of emails significantly.
According to Lifewire, the average size of an email file is 75kb. This equates to around 7,000 words in plain text.
If you receive many newsletters or marketing emails, these can increase the size significantly. Equally, attachments can be many MB each.
It is difficult to say how many emails 100Mb is, but if you had 100 emails, each with one Mb attachment, this would quickly use up your email quota. That being said, compression will significantly reduce the size of emails in your mailbox.