My Mailbox Is Full

A mailbox that reaches its storage limit stops accepting new mail, so the fix is either to clear space or to raise the quota, and KPanel shows you exactly where you are against the limit on every mailbox.

Every Kapsule mailbox is created with 10 GB of storage. That is a lot of correspondence, but a mailbox that has been running for years, or one that receives large attachments, will get there eventually. This article covers how to see your usage, what actually happens as you approach the limit, how to reclaim space, and how to move the mailbox to a larger quota.

Checking Your Usage

Sign in to KPanel and click Email in the left sidebar.
Click the mailbox you want to check.

The header band shows a quota pill and a storage bar reading, for example, "4.1 GB of 10 GB - 41% used". The bar changes colour as it fills, turning amber past three quarters and red as it approaches the limit, so a glance down the mailbox list tells you which accounts need attention.

What Happens as a Mailbox Fills

Kapsule watches mailbox usage and reacts at two points:

Usage	What happens
Under 80%	Nothing. Normal operation.
80% to 99%	A warning is raised on the account and you are emailed once, with the heading "Your mailbox is almost full".
100% and over	A critical alert is raised and you are emailed with the heading "Your mailbox is full".

The warning mail is deliberately blunt about the consequence: "When a mailbox is over its limit, incoming mail can start to bounce. Clear out large messages or upgrade the mailbox."

A full mailbox does not queue mail for later. Once the mailbox is over its limit the mail server starts refusing new messages, and the sender receives a bounce telling them the recipient's mailbox is full. Nothing you already have is deleted, but mail sent to you during that period is not held anywhere and will not arrive later. Act on the 80% warning rather than waiting for the 100% one.

Alerts fire once per level, not repeatedly, so if you clear space and fill up again you will be told again.

Reclaiming Space

Work in this order. The first two steps usually recover more than people expect.

1. Empty Junk and Trash

Deleted mail and quarantined junk still occupy the quota until the folders are emptied. Open webmail and empty both. On a mailbox that has been running for a few years this alone can free several gigabytes.

The Spam filter tab in KPanel also has a quarantine view of the Junk folder, where you can mark anything legitimate as Not spam to move it to the Inbox and delete the rest.

2. Find the Large Messages

Almost all mailbox storage is attachments. In webmail, sort a folder by size and work down from the top. A handful of design files, video attachments or PDF proofs will usually account for most of the problem.

Save the attachment somewhere else, then delete the message. Deleting the attachment while keeping the mail is not something mail protocols support: the attachment is part of the message.

3. Archive Old Mail You Must Keep

If you cannot delete it and cannot fit it, take it off the server. The Setup tab on the mailbox has an Export Mailbox control that downloads your mail as a standard .mbox file, which every major mail client can import and read offline.

Each export is capped at 5,000 messages. For a large mailbox, export in stages rather than expecting one file to contain everything, and check the file opens before you delete anything from the server.

4. Check What Is Being Delivered Into the Mailbox

A mailbox that fills unexpectedly fast is often receiving more than its owner realises. Check whether it is:

the destination of a forwarder carrying another address's traffic
a member of a distribution group or a mailing list
the target of a catch-all, which delivers every mistyped and randomly guessed address at your domain into one mailbox

A catch-all pointed at a personal mailbox is the single most common cause of a mailbox filling with junk.

Raising the Quota

If the mailbox genuinely needs more room, upgrade it to Email Premium, which raises that mailbox from 10 GB to 50 GB.

Open the mailbox in KPanel.
Go to the Setup tab.
Scroll to the Plan section.
Click the upgrade control and complete checkout.

Email Premium is US$15.00/month per mailbox and includes 50 GB of storage instead of 10 GB, priority spam filtering, a seven-year email archive, and delivery backed by our service level agreement. It is a per-mailbox upgrade, so you can put your busiest address on it without changing anyone else.

The new quota applies to the mailbox as soon as the order completes. There is no export, no reprovisioning and no downtime.

There is no field in the panel to type an arbitrary quota number. Standard mailboxes are 10 GB and Premium mailboxes are 50 GB. Shared inboxes are created with their own 10 GB allocation and are not eligible for the Premium upgrade.

Downgrading Again

You can drop a mailbox back from Premium at any time from the same Plan section. If the mailbox is currently using more than 10 GB, KPanel warns you before it lets you proceed, and the warning is worth reading:

"After downgrading, new incoming mail to this mailbox will be rejected until you reduce storage usage below 10 GB. Your existing emails are not deleted." Get the mailbox under 10 GB first, then downgrade. Doing it the other way round means every message sent to you bounces until you finish the clean-up.

While the change is being applied you may see "Mailbox quota update in progress. Your quota is reverting to 10 GB and will be applied within 24 hours. Your existing mail is safe."

Troubleshooting

The storage bar has not moved after I deleted a lot of mail. Deleted mail sits in Trash until that folder is emptied. Empty Trash and Junk, then reload the mailbox page.

Senders report a bounce but my bar says I am under the limit. Check you are looking at the right mailbox: an alias delivers into a mailbox with a different name. Also check the mailbox status pill is Active rather than Suspended or Paused, since those states refuse mail too.

One person's mail bounces, everyone else's arrives. That is not a quota issue. Read Email Not Receiving and check the Spam filter tab for a block rule on that sender.

My mail client says the mailbox is full but KPanel says otherwise. Some clients cache the quota figure from the last connection. Force a refresh, or open webmail, which always reads the live figure.

I upgraded to Premium and the bar still says 10 GB. Reload the mailbox page. If it still shows the old figure after a few minutes, check the order completed in Billing, then open a support ticket with the mailbox address.

Everything is clean and it still fills up. Something is delivering into it. Work through the forwarder, group, list and catch-all checks above before assuming a fault.