If you’ve received an alarming email with the subject line “EMAIL STORAGE FAILURE”, warning that your mailbox is nearly full and urging you to take immediate action, you may have been targeted by a phishing scam. This fraudulent email claims that your account storage has reached 96.12% of its capacity (e.g., 481.94MB/500MB) and threatens that you will lose the ability to send or receive important emails unless you log in to take corrective measures.
At first glance, such an email may appear authentic, even referencing legitimate-sounding services like Roundcube Webmail or including professional disclaimers. However, these emails are not genuine system notifications. They are carefully designed phishing attempts meant to trick recipients into clicking a malicious link and entering their login credentials on a fake website.
In this article, we will break down everything you need to know about the “Email Storage Failure” email scam: how it works, what makes it so dangerous, and what steps to take if you have already interacted with it.
Scam Overview
The “Email Storage Failure” scam is a phishing campaign designed to exploit recipients’ fear of losing access to their emails. Since email is a critical tool for personal communication, work, and financial management, cybercriminals know that most people will act quickly to avoid disruptions.
Key Elements of the Scam Email
Subject Line Variations
“EMAIL STORAGE FAILURE”
“Mailbox Quota Exceeded”
“Your Email Account is Almost Full”
“Action Required: Mailbox Storage Warning”
“Critical Email Quota Alert”
These subjects are engineered to capture immediate attention and create a sense of urgency.
Storage Warning Details The body of the email typically states that your mailbox is 96% or more full. For example: The email account currently uses 96.12% (481.94 MB/500 MB) of its capacity. If no action is taken, you may experience service interruptions including the inability to send or receive important emails. This specific detail (percentages, MB used) is inserted to add a false sense of legitimacy.
Threat of Service Interruption The message warns that if you fail to act, you will lose the ability to send or receive emails. This fear-based tactic is a hallmark of phishing scams.
Fake Action Button A large button typically labeled “Login Here To Take Action” is included. Instead of fixing any storage issue, this button redirects victims to a fraudulent login page.
Misleading Footer & Branding The email often includes text mentioning Roundcube Webmail Services or other real-sounding companies. It may even contain fake copyright statements and privacy notices to look professional. Example: “Roundcube Web Services, Inc. is a subsidiary of WBM Inc. Webmail is a registered trademark of Roundcube. This message was produced and distributed by Web Services, Inc.” While this sounds legitimate, it is completely fabricated.
Why This Scam Works
Authority: Poses as an official email provider notification.
Urgency: Implies immediate action is necessary to prevent service interruption.
Fear of Loss: No one wants to lose access to their inbox or miss important communications.
Familiar Design: Mimics real webmail storage notifications.
These psychological triggers are the same tactics used in countless phishing campaigns, but they remain effective because they exploit human emotion before logic.
How the Scam Works
To understand the mechanics, let’s break it down into a step-by-step phishing process.
Step 1: The Email Delivery
The victim receives an email with the subject “EMAIL STORAGE FAILURE” or a similar variant. It bypasses spam filters by using carefully crafted text and occasionally compromised servers.
Step 2: The Fake Warning
The body of the email states:
Your storage is nearly full.
If no action is taken, you will not be able to send or receive messages.
A button is provided to “resolve” the issue.
The scam relies on the fact that many real email providers send similar quota alerts, making it believable.
Step 3: The Call-to-Action Link
The victim clicks “Login Here To Take Action”. This is the most critical moment — instead of leading to their legitimate email provider, the button redirects to a phishing page.
Step 4: The Phishing Website
The phishing site is often a clone of a Roundcube Webmail login page or a generic webmail portal.
It prompts the user to enter:
Email address
Password
In some cases, advanced phishing kits may also request recovery codes, 2FA tokens, or secondary email credentials.
Step 5: Credential Theft
Once the victim enters their credentials:
The data is captured and transmitted to the scammers’ server.
The fake site may then display a “login error” or simply redirect to the real Roundcube login page to reduce suspicion.
Step 6: Exploitation of Stolen Data
The stolen email credentials are valuable because:
Email is a master key: Many services (banking, shopping, cloud storage, social media) are tied to your email account. With access, scammers can reset passwords.
Business email compromise: For corporate users, attackers may send fraudulent invoices or impersonate executives to trick colleagues into transferring funds.
Identity theft: Emails often contain sensitive personal documents, financial statements, and private communications.
Spamming & phishing campaigns: The hijacked email may be used to spread further scams.
Sale on dark web markets: Cybercriminals frequently sell harvested credentials in bulk.
What To Do If You Have Fallen Victim To This Scam
If you interacted with the “Email Storage Failure” scam email, immediate action is necessary to minimize damage.
1. Change Your Email Password Immediately
Go directly to your provider’s official login page.
Use a strong, unique password that you have never used before.
2. Enable Two-Factor Authentication (2FA)
Use an authenticator app (Google Authenticator, Authy) rather than SMS for better security.
This adds an extra layer of protection even if your password is stolen.
3. Check Recent Login Activity
Review your account’s login history for suspicious devices or IP addresses.
Log out all active sessions if possible.
4. Revoke Suspicious Connections
Go into account settings and remove any unknown linked applications or permissions.
5. Scan Your Device for Malware
Use a trusted antivirus or anti-malware tool.
Some phishing campaigns also drop malware via attachments.
6. Secure Other Accounts
If you reused the same password elsewhere (banking, shopping, social media), change those passwords immediately.
Enable 2FA on those services too.
7. Notify Your Contacts
Warn colleagues, clients, and friends not to trust suspicious emails from your address.
Scammers may already be using your account to spread more phishing attempts.
8. Report the Scam
Use your email provider’s “Report Phishing” option.
Within the EU, report to your national cybercrime authority.
9. Monitor for Identity Theft
Watch your bank and credit card accounts for unauthorized activity.
Consider freezing your credit reports if financial fraud is suspected.
10. Consider Professional Help
Businesses should involve their IT security team.
Victims of identity theft may benefit from credit monitoring or identity protection services.
Is Your Device Infected? Scan for Malware
If your computer or phone is slow, showing unwanted pop-ups, or acting strangely, malware could be the cause. Running a scan with Malwarebytes Anti-Malware Free is one of the most reliable ways to detect and remove harmful software. The free version can identify and clean common infections such as adware, browser hijackers, trojans, and other unwanted programs.
Malwarebytes works on Windows, Mac, and Android devices. Choose your operating system below and follow the steps to scan your device and remove any malware that might be slowing it down.
Malwarebytes for WindowsMalwarebytes for MacMalwarebytes for Android
Run a Malware Scan with Malwarebytes for Windows
Malwarebytes stands out as one of the leading and widely-used anti-malware solutions for Windows, and for good reason. It effectively eradicates various types of malware that other programs often overlook, all at no cost to you. When it comes to disinfecting an infected device, Malwarebytes has consistently been a free and indispensable tool in the battle against malware. We highly recommend it for maintaining a clean and secure system.
Download Malwarebytes
Download the latest version of Malwarebytes for Windows using the official link below. Malwarebytes will scan your computer and remove adware, browser hijackers, and other malicious software for free.
(The above link will open a new page from where you can download Malwarebytes)
Install Malwarebytes
After the download is complete, locate the MBSetup file, typically found in your Downloads folder. Double-click on the MBSetup file to begin the installation of Malwarebytes on your computer. If a User Account Control pop-up appears, click “Yes” to continue the Malwarebytes installation.
Follow the On-Screen Prompts to Install Malwarebytes
When the Malwarebytes installation begins, the setup wizard will guide you through the process.
You’ll first be prompted to choose the type of computer you’re installing the program on—select either “Personal Computer” or “Work Computer” as appropriate, then click on Next.
Malwarebytes will now begin the installation process on your device.
When the Malwarebytes installation is complete, the program will automatically open to the “Welcome to Malwarebytes” screen.
On the final screen, simply click on the Open Malwarebytes option to start the program.
Enable “Rootkit scanning”.
Malwarebytes Anti-Malware will now start, and you will see the main screen as shown below. To maximize Malwarebytes’ ability to detect malware and unwanted programs, we need to enable rootkit scanning. Click on the “Settings” gear icon located on the left of the screen to access the general settings section.
In the settings menu, enable the “Scan for rootkits” option by clicking the toggle switch until it turns blue.
Now that you have enabled rootkit scanning, click on the “Dashboard” button in the left pane to get back to the main screen.
Perform a Scan with Malwarebytes.
To start a scan, click the Scan button. Malwarebytes will automatically update its antivirus database and begin scanning your computer for malicious programs.
Wait for the Malwarebytes scan to complete.
Malwarebytes will now scan your computer for browser hijackers and other malicious programs. This process can take a few minutes, so we suggest you do something else and periodically check the status of the scan to see when it is finished.
Quarantine detected malware
Once the Malwarebytes scan is complete, it will display a list of detected malware, adware, and potentially unwanted programs. To effectively remove these threats, click the “Quarantine” button.
Malwarebytes will now delete all of the files and registry keys and add them to the program’s quarantine.
Restart your computer.
When removing files, Malwarebytes may require a reboot to fully eliminate some threats. If you see a message indicating that a reboot is needed, please allow it. Once your computer has restarted and you are logged back in, you can continue with the remaining steps.
Once the scan completes, remove all detected threats. Your Windows computer should now be clean and running smoothly again, free of trojans, adware, and other malware.
If your current antivirus allowed this malicious program on your computer, you may want to consider purchasing Malwarebytes Premium to protect against these types of threats in the future. If you are still having problems with your computer after completing these instructions, then please follow one of the steps:
Malwarebytes for Mac is an on-demand scanner that can destroy many types of malware that other software tends to miss without costing you absolutely anything. When it comes to cleaning up an infected device, Malwarebytes has always been free, and we recommend it as an essential tool in the fight against malware.
Download Malwarebytes for Mac.
You can download Malwarebytes for Mac by clicking the link below.
When Malwarebytes has finished downloading, double-click on the setup file to install Malwarebytes on your computer. In most cases, downloaded files are saved to the Downloads folder.
Follow the on-screen prompts to install Malwarebytes.
When the Malwarebytes installation begins, you will see the Malwarebytes for Mac Installer which will guide you through the installation process. Click “Continue“, then keep following the prompts to continue with the installation process.
When your Malwarebytes installation completes, the program opens to the Welcome to Malwarebytes screen. Click the “Get started” button.
Select “Personal Computer” or “Work Computer”.
The Malwarebytes Welcome screen will first ask you what type of computer are you installing this program, click either Personal Computer or Work Computer.
Click on “Scan”.
To scan your computer with Malwarebytes, click on the “Scan” button. Malwarebytes for Mac will automatically update the antivirus database and start scanning your computer for malware.
Wait for the Malwarebytes scan to complete.
Malwarebytes will scan your computer for adware, browser hijackers, and other malicious programs. This process can take a few minutes, so we suggest you do something else and periodically check on the status of the scan to see when it is finished.
Click on “Quarantine”.
When the scan has been completed, you will be presented with a screen showing the malware infections that Malwarebytes has detected. To remove the malware that Malwarebytes has found, click on the “Quarantine” button.
Restart computer.
Malwarebytes will now remove all the malicious files that it has found. To complete the malware removal process, Malwarebytes may ask you to restart your computer.
After scanning, delete any detected threats. Your Mac should now be free from adware, unwanted extensions, and other potentially harmful software.
If your current antivirus allowed a malicious program on your computer, you might want to consider purchasing the full-featured version of Malwarebytes Anti-Malware to protect against these types of threats in the future. If you are still experiencing problems while trying to remove a malicious program from your computer, please ask for help in our Mac Malware Removal Help & Support forum.
Run a Malware Scan with Malwarebytes for Android
Malwarebytes for Android automatically detects and removes dangerous threats like malware and ransomware so you don’t have to worry about your most-used device being compromised. Aggressive detection of adware and potentially unwanted programs keeps your Android phone or tablet running smooth.
Download Malwarebytes for Android.
You can download Malwarebytes for Android by clicking the link below.
In the Google Play Store, tap “Install” to install Malwarebytes for Android on your device.
When the installation process has finished, tap “Open” to begin using Malwarebytes for Android. You can also open Malwarebytes by tapping on its icon in your phone menu or home screen.
Follow the on-screen prompts to complete the setup process
When Malwarebytes will open, you will see the Malwarebytes Setup Wizard which will guide you through a series of permissions and other setup options. This is the first of two screens that explain the difference between the Premium and Free versions. Swipe this screen to continue. Tap on “Got it” to proceed to the next step. Malwarebytes for Android will now ask for a set of permissions that are required to scan your device and protect it from malware. Tap on “Give permission” to continue. Tap on “Allow” to permit Malwarebytes to access the files on your phone.
Update database and run a scan with Malwarebytes for Android
You will now be prompted to update the Malwarebytes database and run a full system scan.
Click on “Update database” to update the Malwarebytes for Android definitions to the latest version, then click on “Run full scan” to perform a system scan.
Wait for the Malwarebytes scan to complete.
Malwarebytes will now start scanning your phone for adware and other malicious apps. This process can take a few minutes, so we suggest you do something else and periodically check on the status of the scan to see when it is finished.
Click on “Remove Selected”.
When the scan has been completed, you will be presented with a screen showing the malware infections that Malwarebytes for Android has detected. To remove the malicious apps that Malwarebytes has found, tap on the “Remove Selected” button.
Restart your phone.
Malwarebytes for Android will now remove all the malicious apps that it has found. To complete the malware removal process, Malwarebytes may ask you to restart your device.
When the scan is finished, remove all detected threats. Your Android phone should now be free of malicious apps, adware, and unwanted browser redirects.
If your current antivirus allowed a malicious app on your phone, you may want to consider purchasing the full-featured version of Malwarebytes to protect against these types of threats in the future. If you are still having problems with your phone after completing these instructions, then please follow one of the steps:
Restore your phone to factory settings by going to Settings > General management > Reset > Factory data reset.
After cleaning your device, it’s important to protect it from future infections and annoying pop-ups. We recommend installing an ad blocker such as AdGuard. AdGuard blocks malicious ads, prevents phishing attempts, and stops dangerous redirects, helping you stay safe while browsing online.
Frequently Asked Questions
What is the “Email Storage Failure” email scam?
The “Email Storage Failure” scam is a phishing campaign that pretends your email account is almost full. It typically claims your storage is at 96% capacity and that you risk losing the ability to send or receive emails. The email includes a button labeled “Login Here To Take Action.” If clicked, it redirects you to a fake login page designed to steal your email credentials.
Is the “EMAIL STORAGE FAILURE” message real?
No, it is not real. This message is not sent by Roundcube, Microsoft, Gmail, Yahoo, or any legitimate email service provider. Real providers may notify you of storage limits, but they will never ask you to click a suspicious link or button to “fix” the issue. If you receive such an email, it is a scam and should be ignored or deleted.
How do scammers trick people with this email?
Scammers use urgency and fear tactics. By warning you that your mailbox is almost full and threatening service interruptions, they pressure you into acting quickly. The inclusion of precise percentages like “96.12% full” makes the message look legitimate, increasing the chance that you will click the malicious link without questioning it.
What happens if I click “Login Here To Take Action”?
If you click the button, you will be taken to a phishing site disguised as a real webmail login page. Once you enter your username and password, the scammers collect this information. They may then use your email account to spread more phishing messages, steal sensitive data, or gain access to other services linked to your email.
What can scammers do with my stolen email credentials?
Once scammers have access to your email login details, they can reset passwords for banking, shopping, or social media accounts linked to your email. They may impersonate you to trick your contacts into sending money or sharing sensitive information. For businesses, scammers may attempt invoice fraud or wire transfer scams. Stolen credentials are also often sold on dark web marketplaces.
How can I tell if the “Email Storage Failure” email is fake?
Look for common signs of phishing:
The sender’s address does not match your provider’s official domain.
The email contains urgent language like “take action immediately.”
The message includes suspicious links or buttons.
The email has poor grammar, formatting issues, or unusual phrasing.
The footer may reference companies like Roundcube Web Services but is filled with fabricated details.
If you are unsure, log in directly to your email provider through its official website instead of clicking any links.
What should I do if I entered my password on the phishing site?
If you entered your credentials, take action immediately. First, change your email password from the official login page. Then enable two-factor authentication to add an extra layer of protection. Check your account’s login history for suspicious activity and log out of unknown devices. Revoke any unauthorized app connections and update passwords for other accounts that used the same login details. Finally, report the phishing attempt to your provider and relevant cybercrime authorities.
Can my device get infected with malware from this scam?
Most “Email Storage Failure” scams focus on credential theft rather than malware. However, some phishing campaigns may include malicious attachments or links to sites that attempt to install spyware or trojans. It is always a good idea to scan your device with updated antivirus software after interacting with a phishing email.
How can I protect myself from email phishing scams?
To stay safe, never click links or buttons in suspicious emails. Always verify alerts by logging in through your provider’s official website. Use strong and unique passwords, and enable two-factor authentication on all accounts. Keep your operating system and security tools updated. For businesses, employee training on phishing recognition is essential.
Should I report the “Email Storage Failure” email?
Yes, reporting helps providers and security organizations block future campaigns. You can report phishing directly in your email client or forward the email to reportphishing@apwg.org. In the U.S., you can also report to the Federal Trade Commission (FTC). In the U.K., forward phishing emails to report@phishing.gov.uk. European Union users should report to their national cybercrime authority.
The Bottom Line
The “Email Storage Failure” email scam is a phishing attack designed to steal your email login credentials by convincing you that your account is almost full. While the warning may look professional and urgent, it is not associated with Roundcube or any legitimate provider.
If you receive such an email:
Do not click any links.
Delete it immediately.
If you already entered your information, change your passwords and enable 2FA without delay.
By remaining cautious, verifying suspicious alerts, and practicing good cyber hygiene, you can protect yourself from falling victim to this scam and others like it.
Stelian leverages over a decade of cybersecurity expertise to lead malware analysis and removal, uncover scams, and educate people. His experience provides insightful analysis and valuable perspective.
