--- title: "Open Mail Relay: Why It Is Considered A Spammer’s Dream | 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/open-mail-relay/" --- Content # Open Mail Relay: Why It Is Considered A Spammer’s Dream 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/) ## Open Mail Relay: Why It Is Considered A Spammer’s Dream [Fix Your SPF Errors Now](/content/spf-permerror) Even after all these years, email still remains one of the best sources of communication for any IT organization. When it comes to bulk email delivery, _a mail relay is an easy and effective way to solve the spam and security issues inherent with outgoing email servers_. An open mail relay is a Simple Transfer Mail Protocol (SMTP) server, which is improperly configured and allows an **unauthenticated relay** of email. Spammers connect to the server and forge the sender information of the messages to use it to send an email. ![mail relay smtp](https://media.mailhop.org/duocircle/images/2020/05/mail-gateway-service.png) ### What Is SMTP Relay? In simple terms, [what is SMTP relay](/content/mail-relay-smtp/what-is-smtp-relay) means is _an SMTP relay is a process of transferring an email from one server to another over the Internet_. The SMTP servers are [protected](https://www.vircom.com/blog/top-10-tips-to-secure-your-email-server/) by usernames and passwords to **avoid unauthorized use**. Unfortunately, _when these servers are not protected, then they are called open relays_. ### Why Is It Necessary To Avoid An Open Relay SMTP Server? There are several ways how an open mail relay server can cause damage to your business - It does nothing to identify the original sender of email messages - The spammers can use it to send spam to legitimate users - _Your IP may get blacklisted because of the spammers_, and you will never be able to send mass emails from it - The **business may suffer** financial as well as reputational loss in case of a cyber-attack ![smtp relay gmail](https://media.mailhop.org/duocircle/images/2020/05/online-spam-filtering-service.png)![outbound smtp](https://media.mailhop.org/duocircle/images/2020/05/outbound-spam-filter-office-365.png) ### Who Creates An Accessible Mail Relay SMTP? No one intentionally creates an open mail relay. There are several ways it gets established, such as follows - **Misconfigured** external-facing security appliances - **Security flaws** in [SMTP relay service](/content/mail-relay-smtp/smtp-relay-service) - Using an old mail relay server software ### How To Avoid The Use Of Open Mail Relay Server? To avoid or close an open mail relay, you can do the following - Ask your IT group to configure your [mail relay SMTP](/content/mail-relay-smtp) server to sends mail from only known domains or IP addresses - Ensure proper **security protocols** that allow access to only those with a username and password - Make use of [SMTP relay free](/content/mail-relay-smtp/smtp-relay-free) software options that offer a flexible and powerful SMTP relay service, for example, [SMTP relay Gmail](/content/mail-relay-smtp/smtp-relay-gmail), SMTP relay o365, etc. Some blacklists target open relays actively for blocking the abusive practices of spammers who target these **unsecured servers**. _A common practice among enterprises is to disable the relay function altogether, to avoid this issue_. ![smtp relay free](https://media.mailhop.org/duocircle/images/2020/05/spam-filtering.png) ##### 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. 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