How to identify fake emails like "Mailbox Usage Warning"

What kind of scam is "Mailbox Usage Warning"?

We have inspected the email and found that it is a fraudulent message regarding the recipient's mailbox storage. It uses urgent language to trick recipients into taking immediate action. The goal is to steal personal information through a fake website. Scams of this type are classified as phishing emails.

More about the "Mailbox Usage Warning" scam email

This phishing email warns that the recipient's mailbox is nearly full and provides fake details about the current storage usage and the maximum limit. It urges the user to manage their storage to avoid interruptions in sending or receiving messages. Its purpose is to trick the recipient into clicking the provided link ("Storage Management" button).

The link leads to a fake website made to look like the Gmail login page, designed to steal email login credentials. If the scammers get access, they can log into the victim's email account, read private messages, gather sensitive information, and send phishing emails to others.

These stolen credentials might also be used to break into other accounts, such as social media or banking services. This can result in identity theft, financial loss, and further misuse of personal data. In many cases, the stolen information is also sold to others on the dark web.

Similar scam emails in general

These types of emails are commonly used to lure users into entering their login credentials (or other details) on fake websites. They often appear to come from legitimate companies, organizations, or individuals and use alarming messages to deceive recipients into taking quick action. Falling for such scams can lead to identity theft, monetary loss, and even computer infections.

Some examples of scam emails similar to the one we reviewed are "Leave Request Form", "Human Resource Internal Memo", and "OneDrive - You Have A New Document".

How do spam campaigns infect computers?

Cybercriminals commonly spread malware by sending emails with infected attachments or links. These attachments might look like regular files, such as PDFs, Word documents, ZIP folders, or executables, but they can contain hidden malware that activates if opened or if macros are enabled (or other actions are taken).

Emails used to deliver malware can also include links to fake or compromised websites, which may try to trick users into downloading malware themselves or download malware automatically after visiting.

How to avoid installation of malware?

Download software only from official websites or trusted app stores. Keep your operating system and all software up to date. Use reliable antivirus or security software and run regular full system scans. Be cautious with email attachments and links. Do not open them if emails are unexpected, irrelevant, and (or) sent from unknown addresses.

Avoid downloading pirated software, cracking tools, or key generators. Do not interact with suspicious pop-ups, ads, or links on untrustworthy websites, and never allow dubious websites to send notifications. If you have already opened malicious attachments, we recommend running a scan with Combo Cleaner Antivirus for Windows to automatically eliminate infiltrated malware.

Text presented in the "Mailbox Usage Warning" email letter:

Subject: You will stop to send or receive messages shortly

Mailbox Usage Warning

Hello ******** , your mailbox is almost full!
4.90 GB used
5.00 GB limit
Storage Management

Mailbox address: ********

This email is to notify you that you are reaching your mailbox storage limit.

Unsubscribe From This List | Manage Email Preferences

Phishing website is used in this scam:

Instant automatic malware removal:

Manual threat removal might be a lengthy and complicated process that requires advanced IT skills. Combo Cleaner is a professional automatic malware removal tool that is recommended to get rid of malware. Download it by clicking the button below:

By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. To use full-featured product, you have to purchase a license for Combo Cleaner. 7 days free trial available. Combo Cleaner is owned and operated by RCS LT, the parent company of PCRisk.com.

Quick menu:

• What is Mailbox Usage Warning phishing email?
• Types of malicious emails.
• How to spot a malicious email?
• What to do if you fell for an email scam?

Types of malicious emails:

Phishing Emails

Most commonly, cybercriminals use deceptive emails to trick Internet users into giving away their sensitive private information, for example, login information for various online services, email accounts, or online banking information.

Such attacks are called phishing. In a phishing attack, cybercriminals usually send an email message with some popular service logo (for example, Microsoft, DHL, Amazon, Netflix), create urgency (wrong shipping address, expired password, etc.), and place a link which they hope their potential victims will click on.

After clicking the link presented in such email message, victims are redirected to a fake website that looks identical or extremely similar to the original one. Victims are then asked to enter their password, credit card details, or some other information that gets stolen by cybercriminals.

Emails with Malicious Attachments

Another popular attack vector is email spam with malicious attachments that infect users' computers with malware. Malicious attachments usually carry trojans that are capable of stealing passwords, banking information, and other sensitive information.

In such attacks, cybercriminals' main goal is to trick their potential victims into opening an infected email attachment. To achieve this goal, email messages usually talk about recently received invoices, faxes, or voice messages.

If a potential victim falls for the lure and opens the attachment, their computers get infected, and cybercriminals can collect a lot of sensitive information.

While it's a more complicated method to steal personal information (spam filters and antivirus programs usually detect such attempts), if successful, cybercriminals can get a much wider array of data and can collect information for a long period of time.

Sextortion Emails

This is a type of phishing. In this case, users receive an email claiming that a cybercriminal could access the webcam of the potential victim and has a video recording of one's masturbation.

To get rid of the video, victims are asked to pay a ransom (usually using Bitcoin or another cryptocurrency). Nevertheless, all of these claims are false - users who receive such emails should ignore and delete them.

How to spot a malicious email?

While cyber criminals try to make their lure emails look trustworthy, here are some things that you should look for when trying to spot a phishing email:

• Check the sender's ("from") email address: Hover your mouse over the "from" address and check if it's legitimate. For example, if you received an email from Microsoft, be sure to check if the email address is @microsoft.com and not something suspicious like @m1crosoft.com, @microsfot.com, @account-security-noreply.com, etc.
• Check for generic greetings: If the greeting in the email is "Dear user", "Dear @youremail.com", "Dear valued customer", this should raise suspiciousness. Most commonly, companies call you by your name. Lack of this information could signal a phishing attempt.
• Check the links in the email: Hover your mouse over the link presented in the email, if the link that appears seems suspicious, don't click it. For example, if you received an email from Microsoft and the link in the email shows that it will go to firebasestorage.googleapis.com/v0... you shouldn't trust it. It's best not to click any links in the emails but to visit the company website that sent you the email in the first place.
• Don't blindly trust email attachments: Most commonly, legitimate companies will ask you to log in to their website and to view any documents there; if you received an email with an attachment, it's a good idea to scan it with an antivirus application. Infected email attachments are a common attack vector used by cybercriminals.

To minimise the risk of opening phishing and malicious emails we recommend using Combo Cleaner Antivirus for Windows. 

Example of a spam email:

What to do if you fell for an email scam?

• If you clicked on a link in a phishing email and entered your password - be sure to change your password as soon as possible. Usually, cybercriminals collect stolen credentials and then sell them to other groups that use them for malicious purposes. If you change your password in a timely manner, there's a chance that criminals won't have enough time to do any damage.
• If you entered your credit card information - contact your bank as soon as possible and explain the situation. There's a good chance that you will need to cancel your compromised credit card and get a new one.
• If you see any signs of identity theft - you should immediately contact the Federal Trade Commission. This institution will collect information about your situation and create a personal recovery plan.
• If you opened a malicious attachment - your computer is probably infected, you should scan it with a reputable antivirus application. For this purpose, we recommend using  Combo Cleaner Antivirus for Windows.
• Help other Internet users - report phishing emails to Anti-Phishing Working Group, FBI’s Internet Crime Complaint Center, National Fraud Information Center and U.S. Department of Justice.

Frequently Asked Questions (FAQ)

Why did I receive this email?

Receiving a scam email usually means your email address was collected from a data breach, a hacked website, or a similar source. These messages are typically are not personally targeted.

I have provided my personal information when tricked by this email, what should I do?

If scammers have captured your login details, immediately change the passwords for all potentially compromised accounts. If you are locked out, contact the support team of the affected platform to regain access.

I have downloaded and opened a malicious file attached to an email, is my computer infected?

The chance of infection depends on the file type and how the user interacts with it. For example, if a malicious executable file is opened, malware can infiltrate the system immediately. Files like PDFs or Office documents are usually less risky, but turning on features like macros can activate malware.

I have read the email but did not open the attachment, is my computer infected?

Reading an email alone cannot cause harm to a device. Malware can be executed only after opening malicious links or files.

Will Combo Cleaner remove malware infections that were present in email attachment?

Combo Cleaner can detect and eliminate many types of known malware. Because some threats may be deeply embedded in the system, running a full system scan is essential to find and remove all infections.