MACHINE-GENERATED EMAIL SECURITY

Secure SMTP Relay for Application and AI-Generated Email

Secure transactional email across applications, SaaS platforms, and AI agents. Control who can send using your domains.

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SER Overview

Secure transactional email from applications and AI agents

Secure Email Relay helps you control, protect, and deliver transactional email—such as notifications, statements, invoices, and password resets—from applications, SaaS platforms and third-party services, as well as AI-generated email. It authenticates approved senders, supports DMARC, protects sensitive data, and helps keep business-critical email flowing.

Maintain control of your email identity

Govern every application, service, and AI agent that sends email using your domains from a single control point.

Keep trusted communications flowing

Protect transactional email while reducing the risk of compromised senders, authentication failures, and reputation damage.

Secure application and AI-driven growth

Apply consistent authentication, compliance, and data protection controls as automated email volumes expand.

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An Expanding Sender Base

Your trusted email identity extends beyond the inbox

A growing share of business-critical email comes from systems, applications, and services. As senders increase, it becomes harder to identify authorised sources and prevent compromised systems from abusing trusted domains.

Without centralised control, application email can create gaps in security, compliance, and deliverability. Your organisation needs a way to govern every sender, protect domain reputation, and ensure critical communications reach their intended recipients.

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Multi-Layered Email Security

Secure every application email with layered protection

Proofpoint Secure Email Relay protects transactional email with three layers of security. It verifies who can send using your domains, inspects messages for malicious content, and helps enforce compliance across your application-generated email.

Features

Authentication Controls

Allow only approved sources to send email, and support DMARC compliance with DKIM signing.

Threat Protection

Scan outbound email for malicious links, attachments, spam, and malware before delivery.

Compliance Controls

Apply encryption, archiving, and data protection controls to help secure sensitive information.

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Domain Protection

Take control of every sender using your domains

Get centralised control over every source that sends email using your domains. Secure Email Relay helps you identify approved senders, apply authentication consistently, and protect trusted domains from use by unauthorised or compromised sources.

Features

Centralised Sender Governance

Manage approved senders, domains, and email flows from a single control point.

Third-Party Sender Control

Validate SaaS platforms and external providers before they send email using your domains.

Trusted Email Delivery

Separate application email from user email to help protect domain reputation and deliverability.

Accelerated DMARC Adoption

Correlate suspicious activity, compromised accounts, and user risk across environments.

Cloud Migration Support

Move from on-premises relay infrastructure to a scalable cloud-based service.

AI Agent Governance

Extend the same sender controls and protection policies to AI-generated email.

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Take an interactive tour

Explore how Secure Email Relay helps you identify authorised senders, apply consistent security controls, and manage application email from a single control point.

Why Proofpoint

Proofpoint Secure Email Relay vs. traditional SMTP relay services

CapabilityTraditional SMTP Relay ServicesProofpoint Secure Email Relay
Sender governance Focuses primarily on message routing Controls approved applications, SaaS platforms, third-party senders, and AI agents
Domain protection Provides limited controls over sender identity Helps prevent unauthorised or compromised use of trusted domains
Authentication Authentication capabilities vary by deployment Supports DKIM signing and DMARC alignment across senders
Threat protection Often relies on separate security tools Scans outbound email for malicious links, attachments, spam, and malware
Compliance May require additional products Supports encryption, data protection, and archiving policies
Email visibility Visibility is often fragmented across systems Provides centralised oversight of application- and AI-generated email
Application email strategy May mix application and user email traffic Separates application email from user email to help protect reputation and deliverability

Protect trusted communications with Collaboration Security Prime

Secure application-generated email alongside the broader threats targeting your people, identities, and communications through one integrated platform.

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RESOURCES

Get the latest from Proofpoint

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Secure Email Relay

Read the solution brief

Trusting Transactional Email

Read the white paper

Gartner: How to Secure Machine Email Workflows with SMTP Relays

Read the report

Request a demo

Protect application and AI-generated email, control who can send using your domains, and preserve trust in your critical communications.

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Securing application-generated email to protect trusted digital workflows

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Gartner highlights why a dedicated SMTP relay architecture is required

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Frequently Asked Questions

An SMTP relay service routes outbound email from applications, systems, and services to recipients using the Simple Mail Transfer Protocol (SMTP). A secure SMTP relay service does more than route email. It authenticates senders, scans email messages for threats, supports SPF, DKIM, and DMARC, and helps protect email delivery and sender reputation.

Transactional email is an automated email message sent in response to an action or event. Common examples include password resets, authentication codes, invoices, statements, alerts, notifications, and account updates. Unlike bulk marketing emails, transactional email is typically sent one-to-one and supports business-critical workflows.

Many SMTP email services focus primarily on sending email. Secure Email Relay helps organisations control who can send using their domains. It adds capabilities such as sender authentication, threat scanning, DKIM signing, DMARC alignment, encryption, and centralised governance for application-generated email.

SER relay can help organisations meet DMARC requirements by authenticating approved senders and applying DKIM signatures to outbound email. When SPF and DKIM align with your domains, receiving email servers can verify that messages are legitimate, helping improve trust and email delivery.

Secure Email Relay also centralises authentication across application-generated email, making it easier to manage multiple senders and move towards DMARC enforcement with greater confidence.

Secure Email Relay supports email sent from internal applications, SaaS platforms, third-party providers, cloud services, and AI agents. It helps organisations control which sources can send email using their domains while applying consistent security, authentication, and compliance policies. This allows teams to govern a growing number of email sources from a single control point with visibility into who is sending and how messages are being authenticated.

Secure Email Relay helps organisations control which applications, SaaS platforms, third-party providers, and AI agents can send email using their domains. By authenticating approved senders, supporting SPF, DKIM, and DMARC, and providing centralised visibility into email activity, it helps reduce the risk of unauthorised use, domain abuse, and reputation damage.