How do B2B email filters interact with personal email accounts and modify message text?

Email marketer from CSO Online explains that companies may implement policies to restrict or monitor personal webmail usage to protect against data breaches and malware infections, potentially modifying or blocking certain content.

Email marketer from SANS Institute shares that organizations utilize email security gateways to filter and modify email traffic, including personal email accessed on company networks, to prevent malware and data breaches. These gateways can add disclaimers, quarantine suspicious messages, or block access to certain websites.

Email marketer from Email Geeks explains that intercepting the SSL with a proxy has been used in financial services, requiring a cert with a known secret on the employee's browser controlled by the corporation. He also mentions that certificate pinning is going to start defeating that technique unless the browser is completely modified.

Email marketer from Digital Guardian explains that organizations may implement DLP solutions to prevent sensitive data from being exfiltrated through personal email accounts. These solutions can inspect email content, attachments, and metadata to identify and block sensitive information.

Email marketer from Heimdal Security explains that organizations can scan email traffic for malicious content and data breaches. Some solutions can intercept email traffic and modify messages to add warnings or remove malicious attachments.

Email marketer from Spiceworks forum explains that network administrators may block standard ports used by personal email services (e.g., POP3, IMAP, SMTP) to prevent access through desktop email clients. Webmail is then subject to web content filtering.

Email marketer from Information Security Stack Exchange explains that data leakage prevention (DLP) systems can be configured to inspect email content, including personal accounts accessed via company networks. If sensitive information is detected, the system can block the message or alert administrators.

Email marketer from Quora explains that some companies monitor email accounts on company devices, looking for policy violations, and can block specific sites.

Email marketer from Reddit explains that some companies implement policies to monitor or restrict access to personal email accounts on company networks to prevent data leaks or malware infections. This can involve filtering traffic or blocking specific sites.

Expert from Email Geeks mentions that business email filters have zero problem actually modifying the text of your message.

Expert from Email Geeks shares that "Email Isolation allows users to freely access personal email while protecting your people and your organization from advanced attacks" and explains that some B2B filters actually touch personal accounts (gmail and the like) when the user is checking mail at work.

Expert from Word to the Wise explains that B2B filtering does sometimes impact personal accounts (like Gmail and Yahoo). When a person checks their personal email at work, filters will often inspect that traffic.

Documentation from Cisco explains that their Web Security Appliance (WSA) can be configured to scan both inbound and outbound web traffic, including personal email accessed through web browsers. This can involve inspecting the content of emails and modifying them to remove malware or prevent data exfiltration.

Documentation from SonicWall explains that their content filtering service can inspect and control web traffic, potentially modifying or blocking access to certain types of content within personal email services to prevent security risks.

Documentation from Barracuda Networks shares that their email security gateway can modify email content by adding disclaimers, blocking attachments, and scanning for malicious code. This applies to both business and personal email accounts accessed on the corporate network.

Documentation from Google Workspace Admin Help explains that Gmail scans content for spam, phishing, and malware. This scanning process may involve modifications to the message, such as adding warnings or quarantining the email if it's deemed suspicious.

Documentation from Proofpoint explains that targeted attack protection (TAP) can isolate personal webmail usage to protect the organization from advanced attacks. It can also modify the text of your message.

Documentation from Microsoft Learn details how Exchange Online Protection (EOP) can modify email messages. Actions include adding disclaimers, stripping attachments, or blocking messages entirely based on policy configurations and threat assessments. These actions impact both internal and external recipients.