How Can IMAP Be a Security Threat to a Company Explained [Updated 2026 Information]

Many companies secure email logins with MFA and other protections, but IMAP is left open in the background. I’ve seen attackers avoid normal sign-ins and use IMAP instead because it may allow access with just a password. This old setting becomes the easiest way to access company mailboxes without triggering alerts.

However, IMAP can be the security layer of your organisation’s mailboxes. But how? You can take backup via IMAP.  Today, I’m here to walk you through how can IMAP be a security threat to a company, and how to take backup for safety. 

So, don’t skip any crucial section, because complete information is necessary; otherwise, your data can be hacked or stolen. First, let me explain what the IMAP protocol is. 

What Is IMAP and Why Companies Still Use It?

IMAP allows users to access emails from mail servers without downloading them permanently. It keeps messages synced across devices like:

• Outlook
• Gmail
• Mobile phones
• Third-party email clients

Organisations keep IMAP enabled because:

• Old applications, email clients, and scanners use it
• Service accounts were configured for a long time
• By default, IMAP is enabled, like in Gmail, and does not have the knowledge

This is exactly where the problem begins. Next, I’ll explain how can IMAP be a security threat to a company. 

Why Attackers Prefer IMAP Over Modern Login Methods

Recently, I faced a situation where my mailbox was accessed by someone, and that’s when I found the hackers:

• Never logs in through the web.
• Never trigger MFA.
• Access mailboxes using IMAP.

I also found why IMAP is attractive to attackers, and here are the reasons behind the same:

• Supports basic authentication (username + password)
• Bypasses MFA
• Doesn’t trigger modern sign-in alerts
• Rarely monitored by security teams
• Works perfectly for automated password

When modern security policies focus only on browser or app logins, accessing and obtaining IMAP Server information is possible with the user’s credentials.

How Can IMAP Be a Security Threat to a Company?

Here’s how IMAP is not reliable not only for an organisation, but also for an individual:

#1. IMAP Enables Password Spray Attacks

Password spray is one of the most common attacks nowadays. Attackers try common passwords like:

• Welcome@123
• Company@2024
• Password@1

Across thousands of accounts using IMAP.

Because IMAP uses basic authentication, there is no:

• MFA appears
• No conditional access policy blocks it
• No user interaction is required

This allows attackers to silently find valid credentials without triggering alarms. To ensure data continuity, ensure you have a backup or archive IMAP email.

#2. IMAP Bypasses Multi-Factor Authentication (MFA)

IMAP is enabled with basic authentication and does not understand:

• OTP codes
• Authenticator app prompts
• FIDO keys
• Conditional access policies

So even with MFA enabled, attackers can log in using IMAP with only a password. So, your “secured” tenant is still open because of this. Don’t panic! Just export IMAP to PST to ensure a safety net and data continuity, even if your service is hacked or accidentally deleted.

#3. IMAP Is Enabled by Default for Old Service Accounts

How can IMAP be a security threat to a company? Many organisations have:

• Application mailboxes
• Backup mail accounts
• Shared mailboxes configured

These accounts usually:

• Have weak passwords
• Never expire passwords
• Are excluded from MFA
• Still have IMAP enabled

Attackers specifically target these accounts because they will make it easy to access the environment.

#4. IMAP Access Is Harder to Detect in Logs

When attackers use web login, you can see:

• Location
• Device
• Risky sign-in alerts

But IMAP sign-ins often appear as:

• Protocol logins
• No clear device fingerprint
• Less detailed telemetry

In my personal experience, breach get unnoticed because security teams were only monitoring interactive logins.

#5. IMAP Allows Silent Data Exfiltration

Once attackers gain access via IMAP, they don’t change passwords. They can:

• Download entire mailboxes
• Search for credentials and contracts
• Monitor emails to plan BEC (Business Email Compromise) attacks

Because IMAP is designed for syncing emails, and users think this massive data download is normal, and they do nothing, and the hackers start executing Business Email Compromise plans.

#6. IMAP Forgotten During Security Improvements

When companies implement:

• Conditional Access
• MFA enforcement
• Identity protection policies

They usually focus on:

• Browser access
• Outlook app access
• Mobile app access

No one pays attention to IMAP because it’s considered a protocol like POP3, which remains enabled for everyone.

This mismatch between modern security and protocols becomes an advantage for attackers. So, always ensure the modern security measures are enabled, like MFA (Modern Security Authentication). 

#7. IMAP Allows Attackers to Stay Undetected

Even if a user changes their password, attackers:

• Already created app passwords
• Already synced the mailbox
• Continue accessing via IMAP

This allows them to maintain access long after the organisation believes the issue is resolved.

Impact in Compromised Environments

As my personal experience, IMAP misuse led to:

• Financial fraud through BEC
• Data leakage of confidential data
• Exposure of internal credentials shared over email
• Compliance violations (GDPR, HIPAA, ISO)

And in every case, the root cause was the same:

IMAP was enabled and never reviewed. 

Our discussion is not done yet, but I’m sure one thing is clear to you: not checking the IMAP settings is a huge mistake and leads to data breaches, and how can IMAP be a security threat to a company. Additionally, disabling the IMAP will not work, as it is necessary to make data accessible from anywhere and on any device. 

Now, the question is what to do. Don’t worry, next, I’ll explain how to overcome this.

How to Eliminate the IMAP Security Risk

Following these steps, immediately get rid of the cyber attackers:

• Block basic authentication for IMAP, so that cyber attackers have to go for modern authentication to access your mailbox. 
• Replace old apps with modern authentication methods.
• Apply conditional access policies (if possible).
• Monitor sign-in logs specifically for IMAP activity.
• Create strong password policies on every account.
• Remove IMAP from shared and old mailboxes.

So, these best practices will save your account from being hacked and deleted. Not only this, but it is also suggested to take a complete backup of your IMAP account to add an extra layer of safety.

Now you might wonder, how? Let’s understand this in detail.

Improve Security with a Local Data Backup

Even after ensuring the previously discussed security checklist, many times hackers access the user’s mailbox and change the password, so that the real owner can’t log in, and sometimes even experienced IMAP authentication failed error. In these types of scenarios, the user’s data is compromised, and confidential information can leak. 

So, if the data is leaked, we can’t stop it, but if the data is deleted by someone, then a local backup definitely works in this case. 

For the same, I found SysTools IMAP Backup Software can securely export mailbox data from IMAP-enabled accounts to local storage in desired formats, i.e. PST, MBOX, MSG, EML, and PDF. 

Why opt for this?

• Have offline access to critical email data in case attackers delete mailbox content.
• Modify and share what data exists in mailboxes without needing live server access.
• Ensure business continuity even if an account gets compromised or locked.

Having a secure backup allows you to restore the original data in other mail clients also, e.g., if you taken backup in MBOX format, then you can import that into Apple Mail, Thunderbird, etc. 

Beyond restricting IMAP, this is an additional protective layer to access data without the internet and the mail server. So, download now for free, and secure your data from cyber attacks or accidental deletion. 

Author’s Verdict

I’ve learned that companies get breached because old protocols like IMAP are still trusted instead of modern security like MFA. After this discussion, you also understood how can IMAP be a security threat to a company, and how to safeguard data from cyberthreats or permanent data loss. It is suggested to try the specified email backup wizard to backup any IMAP-supported client, like export GoDaddy email to PST.