Email Storage Quotas: What They Are and How to Manage Them

Every day, emails flow in - newsletters, receipts, reports, photos. It all adds up, often without us noticing. Over time, inboxes grow heavier, searches slow down, syncing lags, and backups become more demanding.

Behind the scenes, every email consumes energy—not just to store, but to index, replicate, and maintain. This has a real-world cost, as well as an environmental one. Even though our infrastructure runs on 100% renewable energy, trimming the excess still matters. It’s about reducing digital waste, staying efficient, and doing your bit for a greener internet.

That’s where mailbox quotas come in. A mailbox quota is simply the maximum amount of storage space allocated to your email account. It ensures your inbox doesn’t grow unchecked—and helps prevent a few overflowing mailboxes from affecting service quality or costs for everyone else.

If your needs grow, no problem—upgrades are available. But for many, a little inbox housekeeping goes a long way.

Navigation

• How Mailbox Quotas Work
• Can I increase my mailbox quota?
• I have a mailbox with a quota larger than what should be permitted by my plan. How has this happened?
• Should I upgrade or reduce my usage?
• Am I alerted if I reach my email quota?
• What happens if I exceed my quota?
• What if I just need more space?
• In summary...

How Mailbox Quotas Work

When you create a mailbox, you set its storage quota - that’s the maximum amount of space that mailbox is allowed to use. You might set it to 5 GB, 10 GB, or the maximum allowed on your plan. It’s completely up to you.

With our entry-level hosting plans, the maximum you can assign per mailbox is 8 GB - which is usually plenty, especially with a bit of regular inbox housekeeping. Higher-tier plans offer larger per-mailbox limits.

It’s worth noting: setting a quota doesn’t give that mailbox extra space, it just defines how much of your plan’s total storage it’s allowed to use. Let’s say your hosting plan includes 30 GB of total space. That covers everything—your website, databases, and all mailboxes.

Now imagine one of your colleagues is hoarding ten years’ worth of attachments, expired 2FA codes, marketing newsletters, and “just-in-case” copies of every email they’ve ever sent. Before you know it, they’ve used up the lions share of your space and suddenly everyone else is hitting limits without knowing why.

That’s why setting sensible per-mailbox quotas is important. It helps prevent one overstuffed inbox from consuming all the space in your account, and keeps things running smoothly for everyone.

Can I increase my mailbox quota?

Yes, you can adjust a mailbox’s quota yourself in cPanel, up to the maximum allowed for your hosting plan.

Here’s how those limits break down:

If your overall disk usage shows you’ve got space to spare, here’s how to increase a mailbox quota in cPanel:

1. Log in to cPanel.
2. Go to Email Accounts.
3. Find the mailbox you want to edit and click Manage.
4. Under Storage, update the quota (up to your plan’s limit).
5. Click Update Email Settings to save your changes.

I have a mailbox with a quota larger than what should be permitted by my plan. How has this happened?

You’re not imagining things.

For a long time, cPanel didn’t reliably enforce per-mailbox limits. If your account is a few years old, one or more mailboxes may still be set higher than your plan allows—or even marked as unlimited. And when cPanel added proper quota controls, they didn’t apply retroactively.

To be clear: we’ve always had mailbox limits based on your plan, but this wasn’t strictly enforced and we only contacted customers as we became aware of the over-use. However, we’re working to correct this situation so that quotas match what each plan actually includes.

This isn’t about catching anyone out. It’s about making sure everyone stays within their plan’s allocation, so resources are used fairly and sustainably across all accounts.

Here’s how we’ve handled it:

• If your mailbox was using less than 95% of the maximum limit your plan allows, and had a higher quota than your plan allows, we’ve updated the quota to match the maximum allowance. You might now receive warnings as you get close to that limit - that’s completely normal.
• If your mailbox was already using more than 95% of the maximum quota your plan allows, we didn’t apply the limit right away. Sudden enforcement could’ve caused your mail to bounce - and that’s not how we do things.

We’re now gradually reaching out to a small number of customers who are significantly over their allowance, to ask them to reduce usage or explore upgrade options.

If that’s you — thanks for checking in. We're here to help if you need support tidying up or figuring out the best next step.

Should I upgrade or reduce my usage?

If you're approaching your mailbox quota, you’ve got two options: clear some space, or upgrade to a higher plan.

That said, we strongly encourage starting with a bit of digital decluttering. It keeps your costs lower, reduces waste, and helps us all use fewer resources.

One study found that 68% of stored email is never looked at again. That’s like filling a fridge with food you’ll never eat — and still paying to keep it chilled, backed up, and ready just in case.

So while upgrading is always an option, a little inbox housekeeping often goes a long way.

Here are a few handy things to keep your email life lean, fast, and quota-friendly:

• Use the Email Disk Usage tool in cPanel This lets you sort mailboxes by folder size, see which messages are using the most space, and delete things like all emails older than 3 years, or those with huge attachments. It’s a good spring clean. See our detailed guide here.
• Archive old messages locally If you’re using a mail client like Outlook or Thunderbird, you can move old messages off the server to your computer. You still have access to them - they just don’t count toward your server quota.
• Avoid sending big files as attachments Use services like Dropbox, Google Drive, or WeTransfer instead. If you must send a file, send the link - not the whole package.
• Be mindful of CCs and attachments That 10MB file you sent to five colleagues? It’s now stored in six separate places on your hosting account—your “Sent” folder and each recipient’s inbox. That’s 60MB of storage consumed by a single email.
• And because it’s all happening internally, every copy counts against your plan’s storage. Multiply that by a few large files a week and suddenly, your email usage starts ballooning without you even noticing.
• Watch those email signatures If your email footer includes embedded images instead of ones loaded from a URL, every email you send becomes heavier. Multiply that by dozens of daily emails and it adds up fast.
• Keep an eye on ongoing email hygiene Tidy as you go. Don’t wait for inbox chaos to build up. Do you really need that 2FA code from three weeks ago? That “thanks for signing up” email? That daily newsletter you never open? If you don’t delete it now, it becomes part of the furniture - and far harder to bulk delete later. Train yourself to be a bit of an inbox pedant. Ruthlessly keep only what’s genuinely important. Unsubscribe from newsletters you don’t need.
• It’s the digital equivalent of rinsing your plate instead of leaving it in the sink ‘for later’ (we all know how that ends). A few seconds of pruning now saves hours of cleanup later, and your future self will thank you for it.

Am I alerted if I reach my email quota?

Yes — you’ll get automatic warning emails as your mailbox approaches its quota. These usually kick in around 80%, then again at 90% and 98%, so you’ve got time to take action.

These alerts go to the email address in question, and in some cases to the account’s main contact listed in cPanel too (provided this is configured in cPanel’s contact settings).

If you’re managing multiple mailboxes, it’s worth checking in from time to time via cPanel → Email Accounts to keep an eye on usage.

What happens if I exceed my quota?

If a mailbox hits its quota, it won’t be able to receive any new messages until space is freed up or the limit is increased.

When that happens, anyone who tries to email you will get a bounceback message — usually something like “Mailbox full”. It’s not ideal, but it’s important: it lets the sender know their message didn’t get through, rather than disappearing into the void.

Rest assured, we never delete your old emails. What’s in your mailbox stays put — but new messages will be held back until there’s room.

The best way to avoid this? Respond to quota warning emails as soon as they appear and ensure you don’t hit your mailbox quota.

What if I just need more space?

Sometimes, even after a clear-out, you just need more breathing room.

No problem. You can:

• Upgrade to a higher-tier plan, unlocking more storage per mailbox and overall.
• Or, if you’re really pushing limits, talk to us about a dedicated email server where you can scale to your heart’s content (and your actual usage).

In summary...

We get it. Mailboxes grow like weeds. One minute you're receiving a login code, the next you're storing ten years of newsletters, calendar invites, and "just in case" attachments you’ll probably never open again.

But here’s the thing: a tidy inbox is a happy inbox.

So whether you’re the kind of person who spring cleans aggressively… or the kind who’s still got 47 unread emails from 2017—we’re not judging.

Just know this: you can trim things down, make some space, and feel a bit smug about it.
Or you can upgrade.
Either way, we’ve got your back.