EMailGateway

EMailGateway is a term used to describe a software platform, hardware appliance, or cloud service that acts as an intermediary in email delivery. It typically sits at the boundary between an organization’s internal mail system and external networks, receiving messages from one side and delivering them to the other, while applying policy and security controls. In some configurations, a gateway may also bridge email with other messaging systems or APIs.

Core functions include routing and delivery control based on recipient domains, user identities, or organizational policies; inbound and outbound filtering; spam and malware scanning; content filtering and data loss prevention; and encryption or TLS transport to protect mail in transit. Gateways often enforce signing and authentication standards such as DKIM, SPF, and DMARC, and may provide archiving, journaling, or eDiscovery features. They can also enforce attachment handling rules, rate limits, and sender authentication.

Deployment models vary; gateways may be on-premises, deployed as virtual appliances, or offered as cloud-based services. They are designed to integrate with directory services for user validation, connectors to cloud email providers, and reporting platforms for monitoring and auditing. Architecturally, they commonly comprise an MTA-like core, content filters, antivirus/anti-malware modules, encryption components, and a policy engine, with high availability and scalability considerations.

Use of an EMailGateway can improve security, compliance, and mail delivery reliability in hybrid or multi-provider environments. Potential drawbacks include added latency, administrative overhead, and the need for ongoing rule management and software updates.