Email Storage & Quotas
Every email account has a limited amount of space on the server to store emails and file attachments. The amount of space available which is often referred to as an "email quota" will depend on the hosting or email plan provided by the host/email provider. Having enough storage space for text only emails usually isn't a problem as plain text emails don’t take up much space but file attachments such as high-res images or large documents can quickly eat up megabytes of available space.
What happens when an email quota fills up?
When an email quota for a particular email account fills up on the server new mails will not be received into that email account until enough space is freed up.
What can I do if my email quota is full?
To make space for new emails you will need to delete old emails off of the server. You can do this by deleting old emails in your email client or by logging into the webmail client provided by your host/email provider. It is recommended to keep recent emails and only delete old emails or emails with large file attachments. Make sure you have made a backup of any emails or file attachments you need to retain before deleting emails.
How can I prevent my email quota from filling up?
By using POP3 on your email client and ensuring your email client software is setup to delete emails after downloading you can keep a copy of your emails on your computer and have them deleted off of the server automatically. If you are downloading your emails to multiple devices you can usually set each computer/device to delete downloaded emails off of the server after a number of days. By setting this to 10 days or so instead of instantly you can be sure you have your emails downloaded to all all your devices and always have free space on the server for new emails. These settings can be found in your email client settings on your computer/device but will vary from one email client software to the next.
POP3 vs IMAP
There are two ways or protocols used by email clients to access emails and it is important to use the one best suited to your email quota:
POP3
POP3 is the recommended method when server space is limited. With POP3 emails are downloaded from the server to your computer and automatically deleted off the server. This keeps used space on the the server to a minimum whilst also ensuring all your emails are stored on your computer and accessible even when offline. By using POP3 to download emails from the server to your computer you should have a copy of all your emails on your computer/device. Even when storing emails on your computer you should make regular email backups to avoid permanent data loss.
IMAP
The IMAP protocol is designed to leave emails on the server so your computers/devices can download and view emails off of the server as needed. This can be used to save space on your computer and devices but as emails are stored on the server (or "in the cloud") for longer a larger email quota that consists of at least a few gigabytes is needed to get the most from IMAP.
It is important to remember that no matter what size an email quota is; if email clients are set to leave emails on the server indefinitely without deleting them then eventually the email quota will fill up and new emails will not be able to be received.
Can Email Quotas be increased?
In most cases email quotas can be increased at additional cost however there may also be a maximum limit depending on the host/email provider. As well as an overall storage space limit per email account there is usually also a limit to the maximum size per email which also varies depending on the host/email provider. When sending very large file attachments it is sometimes better to use a file sharing service such as Dropbox and simply include a shared downoad link to the files instead of attaching the files to the email.