by Ryan Ozawa
Article filed in
What is a SMTP Relay?
by Ryan Ozawa
Among the acronyms that make up the architecture of the Internet, SMTP—Simple Mail Transfer Protocol—is one of the oldest. First defined in 1982, this Internet standard was developed to manage one of the very first features of the global network: routing email messages.
Email is a much more complex system today, with more acronyms associated with it such as MX and TLS, but SMTP still serves as the operating manual four decades later. And the way email is routed from sender to receiver still requires mail relays to pass messages along the line, the same way different post offices relay snail mail across the country.
What is a SMTP relay?
A SMTP relay is a special kind of mail relay. Also known as a SMTP server or SMTP provider, a SMTP relay is designed to send large volumes of email messages. Notably, SMTP is not used to accept or receive email.
Almost every email service sends messages via a SMTP relay. While very large companies may operate their own SMTP server, most email systems rely on the SMTP relays of their Internet service provider that is already providing Internet connectivity.
And most SMTP relays are smart hosts, which enhance bulk sending capabilities with other protections to prevent the distribution of spam, viruses, and phishing scams. The best SMTP relays diligently monitor their sender reputation and practice IP warming to avoid getting placed on email blocklists.
The Paubox SMTP relay service
As we mentioned, most individuals and small businesses use the SMTP service that’s provided by their ISP to send email messages.
However, covered entities subject to HIPAA must meet higher standards when it comes to email and handling electronic protected health information (ePHI). The ability to send HIPAA compliant email is an important differentiator.
Paubox integrates with popular email systems like Microsoft 365 or Google Workspace (formerly G Suite) to seamlessly encrypt email messages by default. But since larger companies often manage their own email and their own SMTP setup, Paubox also offers SMTP relay service for the Paubox Email API.
Our SMTP relay service is the easiest to use and most standard of our solutions, and provides on-premise email relaying. This allows customers to relay email traffic to Paubox over an encrypted connection, with Paubox securing every message to every recipient.
With our HITRUST CSF certified product, patients receive encrypted emails directly to their inboxes—no passwords or portals required. Easy to implement with clear documentation, a developer’s experience is as seamless as the email recipient’s.