--- title: "Simplify Business Communication Using Mail Relay SMTP | 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/mail-relay-smtp/" --- Content # Simplify Business Communication Using Mail Relay SMTP 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/) ## Simplify Business Communication Using Mail Relay SMTP A mail relay SMTP service is the best way to manage such automated emails and batch sends. [Fix Your SPF Errors Now](/content/spf-permerror) ###### [EMAIL SECURITY SERVICES](/) ###### [PLANS AND PRICING](/email/outbound-smtp#pricingarea) ###### [OUTBOUND SMTP](/email/outbound-smtp) ### What Is SMTP Relay? _SMTP (Simple Mail Transfer Protocol) is the protocol for delivering outgoing emails._ It is a process to transfer an email from one mail server to another. Imagine that John from Company A wants to send an email message to Tom of Company B. When John sends his outgoing message to Tom, his company’s defined **SMTP Server** connects to Tom’s incoming MX server (receiving mailbox). It then relays the email from John’s mail server to Tom’s mail server. ![mail relay smtp](https://media.mailhop.org/duocircle/images/2020/05/hosted-spam-filter-service.png) ### How Does Mail Relay SMTP Work? _An SMTP server is responsible for delivering the outgoing emails_. However, it does not accept incoming emails. Most businesses use a mail **SMTP relay service**, which is a managed service and helps them send outgoing mails through [Outbound SMTP](/email/outbound-smtp). ### Why Do Enterprises Need An SMTP Relay Service? - It is a convenient way to send emails within your organization, to your employees, or your established or potential clients and customers. - Commonly used ISPs like Gmail put a [cap on the number](https://support.google.com/a/answer/2956491?hl=en) of SMTP relays a user can send per day. Hence, _organizations that need to send bulk marketing and transactional emails require an SMTP relay provider_. ![smtp relay free](https://www.duocircle.com/wp-content/uploads/2020/05/mail-relay-smtp.jpg) ### Caution – Open Mail Relay Can Be A Cybersecurity Threat In earlier times, to facilitate mail deliverability between the separate closed email systems, open mail relays or [third party relays](https://en.wikipedia.org/wiki/Open%5Fmail%5Frelay) were in vogue. However, these are vulnerable and _allow hackers to route large volumes of spam_. The owner of the server unknowingly throws away the computer and network resources to the attacker’s mercy, _who can exploit it to his advantage causing loss of business, system crashes, and equipment damage_. ### Which One To Choose: SMTP Relay Software Or A Managed SMTP Service? While some enterprises choose a **managed SMTP service provider**, some go for installing and maintaining the SMTP relay software themselves. For mail SMTP relay through the software, _the software can easily be installed on any device, and it readily gets integrated into the device’s platform_. The software provider has a list of [outbound SMTP server](/email/outbound-smtp) that enterprises can use for marketing purposes. However, it is tricky to find out which one is the best. _In a managed SMTP service, this gets done through a third party._ ### SMTP Relay Free For Startups And Small Businesses Mail SMTP relay services come in paid or free versions. _The choice of an SMTP service is the prerogative of the enterprise_. Small businesses or companies handle low email volume, and hence, they can go for a free SMTP relay. On the other hand, managing **5,000+ emails per month** requires a premium SMTP relay service. ### Using Google’s Free SMTP Server For SMTP Relay Gmail It is a boon for companies with low email volume. With [SMTP relay Gmail](/content/mail-relay-smtp/smtp-relay-gmail) service, _users can send 100 emails per day or 3,000 per month_. Also, many people shuffle through multiple business and personal emails in today’s busy world. Gmail allows them to consolidate these email addresses with a custom domain. And yes, **it is free!** ### Use SMTP Relay O365 By Creating A Connector _Sending an email using Office 365 does not require setting up an SMTP relay_. Clients can send emails directly to Office 365 without adding a mail SMTP relay. However, businesses can configure it to allow SMTP Relay for [specific IP addresses](https://4sysops.com/archives/allow-exchange-relay-emails-from-certain-ip-addresses/). It eliminates the need for a particular username and password for logging in. Mail SMTP relay services provide enterprises with new tools to make their existing tasks easier, along with revealing new possibilities for marketing. _They can make your day-to-day email tasks much more manageable._ ##### 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":"Simplify Business Communication Using Mail Relay SMTP","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/mail-relay-smtp/","speakable":{"@type":"SpeakableSpecification","cssSelector":[".page-answer",".duo-rich-text p:first-of-type"]},"dateModified":"2021-07-07T16:59:18.000Z","datePublished":"2020-05-27T00:19:17.000Z"},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"DuoCircle","item":"https://www.duocircle.com/"},{"@type":"ListItem","position":2,"name":"Simplify Business Communication Using Mail Relay SMTP","item":"https://www.duocircle.com/content/mail-relay-smtp/"}]}] ```