Troubleshooting “Mailbox Full” Errors Print

Overview

If you’re seeing a “mailbox full” error or emails are bouncing back with a quota warning, it means your email account has reached its allocated storage limit. This guide explains how to check your usage, free up space, and prevent the issue from recurring.

Common Symptoms

• “Mailbox quota exceeded” error messages
• Senders receive bounce-backs when emailing you
• Inability to send or receive new email
• Webmail shows 0 MB free or warnings at the top of the screen

Step 1: Check Mailbox Storage Usage

1. Log into your cPanel account.
2. Go to the Email Accounts section.
3. Next to the affected email address, check the “Storage Usage” bar.
4. Click Manage for that email account to see detailed usage and increase the quota (if allowed).

Step 2: Free Up Mailbox Space

There are several ways to reduce mailbox usage:

Option A: Use Webmail to Delete Emails

1. Visit https://yourdomain.com/webmail and log in.
2. Open your Inbox, Sent, or other large folders.
3. Delete old or unneeded emails, especially those with large attachments.
4. Don’t forget to empty the Trash folder — deleted messages still count toward usage until permanently removed.

Option B: Use Email Client (e.g., Outlook or Thunderbird)

• Set your client to delete older messages or move them to local folders.
• In Outlook, you can archive old emails to a PST file stored on your computer.

Step 3: Increase the Mailbox Quota (if allowed)

1. Log into cPanel.
2. Go to Email Accounts > Manage next to the email address.
3. Under Storage, increase the quota (e.g., from 250MB to 500MB), depending on your hosting plan's limits.
4. Click Update Email Settings to save.

If you've reached the limit of your current plan, you may need to upgrade to a higher hosting tier.

Step 4: Prevent Future Quota Errors

• Use IMAP with a local archive in your mail client to keep your server mailbox clean.
• Regularly delete or archive old messages — especially in the Sent and Junk folders.
• Avoid sending large attachments repeatedly; use cloud links instead (e.g., OneDrive, Google Drive).
• Set up an automatic deletion rule in Webmail or your mail client for older messages.

Need Help?

If you’re still seeing mailbox full errors after cleanup, or you're unsure how to archive email safely, please open a support ticket. We'll assist with identifying large folders and clearing space safely.