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.
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.