How to identify fake emails like "Undelivered Email Reports"

What kind of email is "Undelivered Email Reports"?

After examining this "Undelivered Email Reports" message, we determined that it is spam. This email claims that multiple messages failed to reach the inbox. The goal of this scam is to trick recipients into disclosing their account log-in credentials to a phishing website.

"Undelivered Email Reports" email scam overview

The spam email with the subject "Notification: Undelivered Email(s) in Inbox - Please Investigate and Resolve" (may vary) reports that four messages are in quarantine and did not reach the inbox. Details of two of the supposed emails are provided, and these message concern payments and orders. The recipient can release these emails (including the two with no details given) into their inbox by pressing a button in this fake alert. The withheld messages will be deleted after seven days if they are not released.

It must be emphasized that the information in this email is false, and this mail is not associated with any legitimate service providers. When the "RELEASE ALL" button is clicked, it results in a redirect to a phishing website.

During our analysis, this webpage was down. However, this could be rectified in potential future releases of this spam campaign (i.e., emails will redirect to an operational site). It is highly probable that the promoted phishing website was disguised as an email account sign-in page.

Log-in credentials (or other information) entered into such webpages are recorded and sent to cyber criminals. Stolen emails can be variously misused, including to steal the accounts, platforms, and services linked to them (e.g., social networking, social media, messengers, chats, e-commerce, entertainment services, online banking, money transferring, digital wallets, etc.).

Scammers can steal account owners' identities and request loans or donations from contacts/friends/followers, promote scams, and spread malware by sharing malicious files or links. Hijacked finance-related accounts can be used to make fraudulent transactions or online purchases.

To summarize, by trusting an email like "Undelivered Email Reports" – users can experience severe privacy issues, financial losses, and identity theft.

If you have already provided your log-in credentials to a phishing website (or file) – change the passwords of all possibly compromised accounts and contact their official support without delay.

Phishing spam campaign examples

We have investigated countless spam campaigns; "Your Document Has Been Held In A Queue", "Unsuccessful Mail Delivery Report", and "Mailbox Storage Notification" are just a couple of our latest articles on phishing emails. Aside from log-in credentials, these messages commonly target personally identifiable information and finance-related data.

While the widely held belief that spam emails are poorly written and riddled with spelling/grammatical errors is not untrue, it is not always the case. This mail can be competently put together and even believably disguised as messages from legitimate entities (e.g., service providers, companies, organizations, authorities, etc.).

How do spam campaigns infect computers?

Spam campaigns distribute malware through virulent files that can be attached to or linked inside the emails/messages. These files can be documents (PDF, Microsoft Office, Microsoft OneNote, etc.), executables (.exe, .run, etc.), archives (RAR, ZIP, etc.), JavaScript, and so on.

Malware download/installation is jumpstarted once an infectious file is opened. However, some formats need extra interaction to initiate infection processes. For example, Microsoft Office files require users to enable macro commands (i.e., editing/content), while OneNote documents need them to click on embedded links or files.

How to avoid installation of malware?

We strongly advise caution with incoming emails, PMs/DMs, SMSes, and other communications. Attachments or links present in dubious messages must not be opened, as they can be harmful or virulent.

However, malware is not proliferated exclusively via spam campaigns. Therefore, we recommend being careful while browsing since the Internet is full of fraudulent and malicious content.

Another recommendation is to download only from official and verified channels. Software must be activated using functions/tools provided by genuine developers, as illegal activation ("cracking") tools and third-party updaters may contain malware.

It is essential for device/user safety to have a reputable antivirus installed and kept updated. Security programs must be used to run regular system scans and to remove detected threats. If you've already opened malicious attachments, we recommend running a scan with Combo Cleaner Antivirus for Windows to automatically eliminate infiltrated malware.

Text presented in the "Undelivered Email Reports" spam email letter:

Subject: Notification: Undelivered Email(s) in Inbox - Please Investigate and Resolve

Undelivered Email Reports

Hello ********,
You have 4 emails in quarantine.

SUBJECT: Re:Re: Order No# GN/2425/04231...
TO: "info" (********)
FROM: Sales - Sara Mimbrero | 5/17/2025 1:08:48 a.m.PM | Pending
Release
Delete

SUBJECT: Fwd: Payment ---- Forwarded message ----
TO: "info" (********)
FROM: Accounts | 5/17/2025 1:08:48 a.m. | Pending
Release
Delete

To see remaining 2 undelivered emails held in quarantine, select "Release All" incoming mails from our old version to our new version below:
RELEASE ALL

Emails will be deleted automatically after 7 days. You can change the frequency of these notifications within your email quarantine portal.

Appearance of the "Undelivered Email Reports" spam email (GIF):

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 "Undelivered Email Reports" 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?

Spam emails are not personal, even if they include details relevant to the recipients. These messages are distributed in mass-scale campaigns – therefore, thousands of users receive identical (incredibly similar) emails.

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

If you have provided your log-in credentials – change the passwords of all possibly exposed accounts and inform their official support. However, if you've disclosed other private data (e.g., ID card details, passport scans/photos, credit card numbers, etc.) – immediately contact the appropriate authorities.

I have read a spam email but didn't open the attachment, is my computer infected?

Reading an email does not pose an infection threat; devices are compromised when malicious attachments or links are opened/clicked.

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

File formats can influence infection success rates. Once opened, executables cause infections almost without fail. However, some formats – like documents – might need additional interaction. In these cases, the infection is triggered after macros are enabled, embedded content is clicked, or other actions are performed.

Will Combo Cleaner remove malware infections present in email attachments?

Combo Cleaner is designed to scan computers and eliminate all manner of threats. It is capable of detecting and removing practically all known malware infections. Remember that performing a full system scan is critical since high-end malicious programs typically hide deep with systems.