Email Security Risks: How Business Email Gets Attacked

A message, a sender or a mailbox can get a person to hand over a login, a file or money. An email phishing attack is the first of six ways in. The other five reach the same people by other routes. This guide is for an IT manager or owner in India or the GCC. It sets out the email security risks to picture before you decide where to look first. It explains the risks, but it gives no settings, set-up steps or tool advice.

Email Security Risks in Short: Six Ways an Attack Reaches a Person

An email phishing attack asks for a login. A payment request asks for money. Both start in the same inbox. These email security risks follow the order a person meets them. That order is Signisys’ own grouping, not a standard.

Email Security Risks, 1: The Phishing Message

A phishing message pretends to be a trusted person or company. Its aim is a login, a payment or a click.

The NCSC’s phishing guidance describes scam email or text with links to malicious websites. Those websites may contain malware, or may be designed to trick people into giving up passwords or money. The guidance is from the UK, reviewed on 13 February 2024. It speaks to the technology, operations and security staff of medium to large organisations.

The NCSC also says phishing can hit an organisation of any size and type. This guide takes that as a general point, not as a claim about firm size. A targeted email phishing attack is what the NCSC refers to as spear phishing.

Hypothetical: in an email phishing attack, a finance assistant gets a document-sharing notice from what looks like a colleague. The link opens a sign-in page that is not the real one. In our reading, it can work when the notice arrives at a time the person expects such notices.

Alertness alone does not close the gap. The NCSC says no one can be expected to spot all phishing emails. It also adds that “some phishing attacks will always get through” (UK, February 2024). For the full definition and the types, see the full explanation of phishing.

It can cost you a login, or put malware on a device.

Email Security Risks, 2: A Sender That Is Not Who It Seems

Spoofing means making a message look as if it came from someone else. A look-alike domain, for example, differs from the real one by a letter or two.

The NCSC’s email security and anti-spoofing guidance is UK guidance, as of its October 2019 review. It speaks to cyber security professionals and the public sector. It describes the aim as making it difficult to send fake emails from your organisation’s domains. This also helps the people you do business with, and your brand and reputation.

The NCSC’s phishing guidance (UK, February 2024) adds that attackers can use spoofed emails against your customers or people within your organisation. It also says anti-spoofing controls make it harder to spoof email from your domains.

In our reading, that gives two directions. One sends a forged message to your staff. The other uses your own domain against your customers and suppliers. Among the email security risks here, the second direction puts your own name at stake.

Hypothetical: a supplier’s invoice arrives from a domain one letter off the real one. It lands inside a thread where the real supplier has been writing.

The result can be fraud that looks routine, and a name that customers and suppliers learn to doubt. Nothing here claims that a sender check stops these messages. This guide leaves out the settings themselves. For those, follow the nine set-up steps, in order.

Email Security Risks, 3: The Payment or Bank-Detail Request

The FBI IC3’s 2025 annual report defines business email compromise (BEC) as compromising email accounts and other communications. Its aim is an unauthorised transfer of funds, through social engineering or computer intrusion.

The report records US$3,046,598,558 in BEC losses reported to the US-based IC3 for 2025, about US$3.05 billion. Complaints in the report come from more than 200 countries, but this guide does not use the figure as a measure of India or the GCC. It is the one figure in this guide.

Hypothetical: a message that seems to come from the managing director asks accounts to pay a new supplier today. It adds: keep it quiet. In another, a real supplier “changes” its bank details. Neither message carries a link or an attachment.

In our reading, such a request can work when it looks like normal work. There is also no file to open. The NCSC’s phishing guidance (UK, February 2024) advises verifying important email requests through a second type of communication, such as a phone call. This guide leaves out the full steps.

The cost is money that goes to an account that is not the supplier’s. The FBI IC3 report says that if you discover a fraudulent transfer, time is of the essence. It advises you to contact your financial institution at once and ask for a recall of the funds (US guidance, 2025 report).

Email Security Risks, 4: A Mailbox That Is Taken Over

Account takeover happens when someone who is not the owner signs in to a real mailbox. This risk asks nothing of the person whose mailbox it is.

In our reading, the person behind a taken-over mailbox can read mail to find invoices and the people who approve payments. They can also send messages in the owner’s name, and they may add a forwarding rule, a setting that copies incoming mail to an outside address.

Three clues are worth looking for (our observation, not a source finding):

• A sign-in from an unfamiliar place or device.
• A new forwarding rule to an outside address.
• A bank-detail request outside the normal procedure.

Of the email security risks here, the cost of this one can be private mail read and messages sent in the owner’s name. This guide leaves out sign-in protections and rule monitoring.

Email Security Risks, 5: Links, Attachments and Shared Files

The NCSC’s phishing guidance (UK, February 2024) describes links to malicious websites that may contain malware. In our reading, an attachment can carry malware too. A QR code, for example, hides the web address from a person who reads only the text.

This route hides the harm behind the link. A shared-file notice is one disguise an email phishing attack can use.

Hypothetical: an attachment named like a purchase order opens a document that asks the reader to “enable content”.

Data can also leave by email. A misdirected message or the wrong attachment is a risk of its own. This is our reading, since no source we read puts a figure on it.

It can cost you a login, put malware on a device, or show data to someone who should not see it.

Email Security Risks, 6: When Staff Stay Quiet

The risk after the click is silence. A person who fears a mistake and tells no one gives the attacker more time (our reading).

The sixth of the email security risks concerns the reply to a report, not the message. After an email phishing attack, a report only helps if the person is not afraid to make it. The NCSC’s phishing guidance (UK, February 2024) makes the same point. It advises against a punishment or blame-oriented culture, so that people feel supported to come forward even when they have clicked. That guidance speaks to medium to large organisations and their security staff.

Hypothetical: an employee types a password into a fake page, but feels uneasy and tells no one in IT, because the last colleague who did was told off.

This guide leaves out the fix itself.

It costs time: a longer wait before anyone looks.

Beyond Email: Chat and File-Sharing Tools

The same attacks can also reach people through chat messages and shared-file links. The lure is a message from someone who looks known, whatever the tool (our reading).

• A chat message can carry the same kind of link.
• A shared-file invitation can come from a real, taken-over account, as in the mailbox section above.
• A file shared too widely is a data risk of its own.

No source we read covers chat tools, so this guide gives no figure. It makes no claim about how any tool filters links. Secure collaboration is its own topic, and this guide leaves it out.

What This Article Leaves Out, and Where to Go Next

The NCSC pages are UK guidance, and the FBI IC3 report is US data. We read no source for India or the GCC. This guide therefore says nothing about Indian or GCC rules, volumes or duties. It does not rank the six routes, because the sources do not rank them. It also gives no fix, setting or tool comparison. This guide leaves out settings and fixes, a checklist, and the choice of tool. For that choice, read built-in protection or a dedicated layer. For the checklist, use the 15 yes-or-no tests for your own mail setup.

For the wider topic, see the fuller explanation of email security. To see where a click can lead next, read how a device gets compromised. For the plain-words view of risk in general, see our guide to cyber security risk. The service view also sits in the secure email and collaboration use case.

Signisys provides Email and Collaboration Security, which its solution page describes as protection against phishing, malware and data leaks in everyday tools. It sits within the Endpoint, Network and Zero Trust Security solution and the Cybersecurity Services page. We agree the exact scope for each engagement, while the decisions on each finding stay with your own team.

Email Security Risks FAQ