Your users might not realize that they are reaching the quotas of their mailboxes. Here’s how to check how much space is being used.
FOR A USER: WEBMAIL
If your web host offers Atmail webmail
Seems to me that something as important as informing the user of mailbox space used and available would be a standard feature of any webmail product. But no, the only one I know that has this is Atmail. Where you find this information depends on which user interface you are using. In the basic or simple interfaces, click on “Folders” near the top of the viewport. In the advanced interface, click on Tools – Folder Manager. You will then see a list of your folders and the space used in each:
The exact display will vary depending upon your chosen interface.
If you use the advanced interface and elect to view the start page upon logging in, you can additionally see your mailbox usage there. Near the bottom of the viewport of the start page, notice a section labeled “Mailbox Quota” or “Mailbox Usage” with an indicator of how full your mailbox is. The exact display will vary depending upon your web host. Some web hosts don’t implement this feature.
TODO: Revisit this. Surely the current versions of other popular webmail solutions now offer this. Check in particular SquirrelMail and RoundCube at Pair and Site5. Also add how to check mailbox quotas in mail clients, starting with Thunderbird. The latter probably merits its own article describing both how to check quotas on stock Thunderbird and with the Display Quota add-on.
FOR AN ADMINISTRATOR: CPANEL
If your web host uses cPanel
To see space used per mailbox and mailbox quotas in cPanel, go to Mail – Add/Remove/Manage Accounts and select “Show Disk Space Used”. You will be shown a list of mailboxes and for each the space used and the quota.
To see space used per folder within each mailbox, go to Disk Space Usage and select “Show more directory depth”. You may have to select this option more than once to obtain the depth needed. Mailboxes and folders within them will be shown interspersed with other non-mail directories.
If cPanel doesn’t meet your needs, see how to use ssh below.
FOR AN ADMINISTRATOR: PAIR ACC
If your web host is Pair Networks
To see total space used by mail, open the Pair Account Control Center (ACC), go to Web Site Statistics and in the “Disk Usage” section, select “Details”. Click on a date to see total disk usage for mail (and other categories).
To see mailbox quotas, go to Email Management and in the “Mailbox Usage” section click on “X mailboxes are currently configured”.
Unlike cPanel, the ACC does not provide a means to view space used per mailbox or per folder.
If the ACC doesn’t meet your needs, see how to use ssh below.
FOR AN ADMINISTRATOR: SSH
If your web host offers SSH access
Different web hosts have different file structures according to operating system (BSD, Linux, etc.), mail format (maildir, mbox, etc.), mail server (Dovecot, qmail, etc.), and host preference. For this reason, appropriate terminal commands to see mail usage will differ from host to host. You may find this discussion of my web host’s mail setup illustrative, but this is one case where your mileage will vary. Consult your host’s support documentation.
The well-known command for this task is du -chd X, X being the depth of recursion into subdirectories needed. This is the BSD command; if your host uses Linux, replace -d X with –max-depth X.