--- title: "How Does SMTP Relay Work? | DuoCircle" description: "Join the thousands of organizations that use DuoCircle Find out how affordable it is for your organization today and be pleasantly surprised.Interested in" image: "https://www.duocircle.com/images/og-default.png" canonical: "https://www.duocircle.com/content/smtp-as-a-service/smtp-relay/" --- Content # How Does SMTP Relay Work? Join the thousands of organizations that use DuoCircle Find out how affordable it is for your organization today and be pleasantly surprised.Interested in [ Talk to an Expert → ](/contact/) [ See what we make ](/products/) ## How Does SMTP Relay Work? [Fix Your SPF Errors Now](/content/spf-permerror) _Email is an important day-to-day communication tool all sorts of businesses use_. In most cases, a regular email provider isn’t able to provide the power needed to mass send emails to prospects and clients. So you need to look to a third party for that. By gaining a basic understanding of how **SMTP relay** works, you’ll be better able to choose the right [SMTP service provider](/content/smtp-as-a-service/smtp-service) for your organization. ![outbound smtp port](https://media.mailhop.org/duocircle/images/2019/02/display-name-spoofing-protection.png) ### What is an SMTP? An SMTP is a “[Simple Message Transfer Protocol](https://whatis.techtarget.com/definition/SMTP-Simple-Mail-Transfer-Protocol).” _Your email client uses this protocol to send your emails out_. But how does it get delivered? Through your organization’s [SMTP server](/content/smtp-as-a-service/smtp-server). These servers are similar to ordinary ones in that they provide the power to get emails from one inbox to another. MORE: About [email pricing](/content/smtp-as-a-service/email-pricing) ### How SMTP relay works If you’re planning on sending bulk and **transactional emails**, you’ll need to utilize [SMTP relay](https://www.techopedia.com/definition/30013/smtp-relay). _As the name implies, this process works like a relay race_. _When you send emails from your domain name to another one, those emails can’t be delivered on the same SMTP server_. Yours needs to communicate with the recipients’ SMTP servers to “relay” the information. Because of this logic, you won’t need [SMTP relay service](/content/smtp-as-a-service/smtp-relay-service) if you’re only planning on sending emails to people within your business. Emails will be delivered through the same SMTP server. MORE: Get [free SMTP server](/content/smtp-as-a-service/free-smtp-server) ![outbound smtp settings](https://media.mailhop.org/duocircle/images/2019/02/brand-forgery-components.png)![commercial smtp server](https://media.mailhop.org/duocircle/images/2019/02/phish-protection-bundled.png) ### SMTP relay service from a third party Although email providers allow for **SMTP relay service**, it’s most likely not enough for your email marketing needs. When you’re working with a cap, it can be hard to accomplish your goals. Also, if you try to send marketing emails from your organization’s domain, they can quickly get marked as spam, which hurts your sending reputation. _A third-party_ _SMTP relay server provider_ _can ensure that your protection is unharmed and that you get good deliverability_. _Some even come with domain name anti-spoofing within an email protection suite_. This extra bit of security won’t just protect your company, but also your customers. So when you’re searching for the best [SMTP as a service](/content/smtp-as-a-service), keep in mind that you need a provider that’ll maintain your sending reputation so you can maximize your email marketing efforts. MORE: Know [SMTP Pricing](/content/smtp-as-a-service/smtp-pricing) ##### Join the thousands of organizations that use DuoCircle --- Find out how affordable it is for your organization today and be pleasantly surprised. [Outbound SMTP - Sign Up FREE](/email/outbound-smtp)Interested in our Partner Program for MSPs and VARs? Visit Our [MSP Partner Program](/msp-partner-program). ## Ready to talk? Same-day response from someone technical. We tell you yes or no quickly. If yes, we get to work. [Talk to an Expert→](/contact/)[See what we make](/products/) ```json {"@context":"https://schema.org","@type":"Organization","name":"DuoCircle LLC","url":"https://www.duocircle.com","logo":{"@type":"ImageObject","url":"https://www.duocircle.com/images/duocircle-logo.png"},"description":"DuoCircle is a portfolio of specialized email products covering protection, authentication, delivery, and routing. We deliver about 90% of category-leader capability at roughly half the price, backed by experts who own the outcome. Trusted by 50,000+ organizations since 2014.","subOrganization":[{"@type":"Organization","@id":"https://www.wikidata.org/wiki/Q138898167","name":"DMARC Report","url":"https://dmarcreport.com"},{"@type":"Organization","@id":"https://www.wikidata.org/wiki/Q138897474","name":"AutoSPF","url":"https://autospf.com"},{"@type":"Organization","@id":"https://www.wikidata.org/wiki/Q138897912","name":"Phish Protection","url":"https://www.phishprotection.com"}],"sameAs":["https://www.linkedin.com/company/duocircle","https://x.com/duocirclellc","https://www.facebook.com/duocirclellc","https://www.g2.com/products/phish-protection-by-duocircle/reviews","https://github.com/duocircle","https://www.crunchbase.com/organization/duocircle-llc"],"contactPoint":{"@type":"ContactPoint","contactType":"customer support","url":"https://support.duocircle.com"},"knowsAbout":["Email Security","Email Authentication","SPF","DKIM","DMARC","Phishing Protection","Spam Filtering","SMTP Relay","Email Deliverability","Email Forwarding"]} ``` ```json {"@context":"https://schema.org","@type":"WebSite","name":"DuoCircle LLC","url":"https://www.duocircle.com","description":"DuoCircle is a portfolio of specialized email products covering protection, authentication, delivery, and routing. We deliver about 90% of category-leader capability at roughly half the price, backed by experts who own the outcome. Trusted by 50,000+ organizations since 2014.","publisher":{"@type":"Organization","name":"DuoCircle LLC","url":"https://www.duocircle.com","logo":{"@type":"ImageObject","url":"https://www.duocircle.com/images/duocircle-logo.png"},"description":"DuoCircle is a portfolio of specialized email products covering protection, authentication, delivery, and routing. We deliver about 90% of category-leader capability at roughly half the price, backed by experts who own the outcome. Trusted by 50,000+ organizations since 2014.","subOrganization":[{"@type":"Organization","@id":"https://www.wikidata.org/wiki/Q138898167","name":"DMARC Report","url":"https://dmarcreport.com"},{"@type":"Organization","@id":"https://www.wikidata.org/wiki/Q138897474","name":"AutoSPF","url":"https://autospf.com"},{"@type":"Organization","@id":"https://www.wikidata.org/wiki/Q138897912","name":"Phish Protection","url":"https://www.phishprotection.com"}]}} ``` ```json [{"@context":"https://schema.org","@type":"WebPage","name":"How Does SMTP Relay Work?","description":"Join the thousands of organizations that use DuoCircle Find out how affordable it is for your organization today and be pleasantly surprised.Interested in ","url":"https://www.duocircle.com/content/smtp-as-a-service/smtp-relay/","speakable":{"@type":"SpeakableSpecification","cssSelector":[".page-answer",".duo-rich-text p:first-of-type"]},"dateModified":"2023-08-02T13:18:21.000Z","datePublished":"2019-04-24T17:50:05.000Z"},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"DuoCircle","item":"https://www.duocircle.com/"},{"@type":"ListItem","position":2,"name":"How Does SMTP Relay Work?","item":"https://www.duocircle.com/content/smtp-as-a-service/smtp-relay/"}]}] ```