How SMTP email service is helpful for your business.

SMTP stands for Simple Mail Transfer Protocol and is a digital communication protocol that helps in sending/receiving email messages. SMTP is the technology used behind your email clients to carry all your emails properly to the designated users and helps in receiving all emails to your inbox, as well.

What Is An SMTP Relay Provider?

In a free SMTP relay setup, the message is passed on to the receiver’s SMTP server to get the email to the intended recipient in a proper manner, the same way a baton is passed between players in a relay race.

An SMTP relay, also called SMTP relay software, makes use of the cloud to transmit your messages. When a message is ready for delivery, the SMTP relay service provider queues all messages and sends them to their designated recipient SMTP servers. If the message could not be delivered, it sends a Non-Delivery Report to the sender with detailed information on the non-delivery of the email message.

How Does An SMTP Relay Service Work?

The moment you hit the send button from your email client, the SMTP relay service is notified of an email message to be sent. The SMTP relay service queues the messages in the delivery message queue. Then every email is sorted out to find the domain name from the email address to determine the recipient to whom the email needs to be sent. The next step in the message relay is to contact the Message Delivery Agent of the recipient SMTP server, and the email is handed over. The recipient SMTP server checks the email and delivers it to the inbox of the recipient.

Why Your Business Needs An SMTP Relay Service?

Email messages play a crucial role in many organizations for communicating with people within the organization, as well as customers, suppliers, dealers, etc. When the email server is down or is not working correctly, the whole communication channel to the organization is blocked.

Hence, enterprises need to have a dependable SMTP relay service that will help in hassle-free communication. There are instances when your IP gets blacklisted, and you may not be receiving emails or emails sent by you are not delivered. But when you use an SMTP relay service, it takes care of handling email related issues, including IP blacklisting or email reputation issues that cause all your emails to be sent to the junk folder.

When businesses use third-party mail relay services like SendGrid or MailChannel, they can stay relaxed. All email related issues are taken care of by the dedicated service.

Steps In SMTP Email Delivery

The third-party SMTP relay services carry out a lot of steps in the process of email delivery:

  • The first step is to identify the original sender of the email message. Say, for example, if the email is not sent from an email client, but is sent using a PHP script, then the service determines the user who posted it along with the script name, etc.
  • Apart from looking for the original sender, these SMTP relay services also make use of quality phishing and spam filters to check any threat of malicious content in both incoming and outgoing emails.
  • There is also an internal reputation rating system that scans for the sender of the emails and their reputation ratings as well.
  • The service also checks whether the designated recipients of the email are spam traps, and if it finds any, then those email messages will be quarantined. Spam traps are not real email addresses but are used as a fraud management tool to identify and block spam messages.
  • If the services note any of the issues mentioned above in the emails, then those emails will be rejected and not sent to the recipient’s inbox. Sometimes, suspicious emails are flagged, and all emails in the future from that email address will be closely monitored.
  • But when there are no issues, the emails will be delivered by contacting the recipient SMTP service.
  • Some SMTP relay services also provide you with automated notifications that alert you immediately if there is any issue with your email traffic.
  • The job of an SMTP relay service doesn’t end when the email gets delivered, but it waits for the response from the recipient SMTP servers. And these responses are categorized and stored in the internal reputation system.

In case the response from the SMTP server is like “Message Blocked due to spam – 550 5.7.1,” then it indicates that the message sent is spam. It brings down the reputation rating of the email sender, which is stored in the internal reputation system. When the service sees any email messages from the sender again, the emails will be immediately blocked.

Besides monitoring the response from the recipient SMTP server services, some 3rd party SMTP services also look for the feedback loop created when the email receiver marks the message as spam. The service also alerts the user that their email is marked as spam by the recipient.

Benefits Of Choosing The Best SMTP Relay Service

Choosing the right SMTP relay service can provide the enterprise with a lot of benefits, including:


When you have the right SMTP relay service at your disposal, your IT administrators can devote their time to other productive works than continually looking at email-related issues. Having the best SMTP relay service can save you a lot of time and effort.

Avoid Email Delivery Problems

Remember that your emails will be sent to junk folders not only because of your reputation issues but also because of the poor reputation of your free SMTP service provider. Hence, while choosing an SMTP server, better look for an SMTP relay service provider with a solid reputation. One of the significant advantages of having an SMTP relay service is that it helps in avoiding email delivery issues to a great extent. With the best SMTP relay service at your disposal, you never need to worry about your emails getting delivered to junk folders.

Maintain Your Reputation Ratings

Choosing the best email relay service not only ensures that you don’t face any email delivery issues but also helps in protecting the organization’s reputation rating as well.

How To Choose The Best Free SMTP Relay Service

When it comes to choosing the best SMTP relay service, you need to consider certain factors before arriving at a final decision, such as the following:

  • If the service can integrate easily into your website or application.
  • The kind of technical support provided by the SMTP relay service.
  • Ease of use.
  • Ease of setting up.
  • Email deliverability.
  • Pricing.


SMTP mail relay service not only helps in the delivery of emails without any issues, but it also helps in saving a lot of time and effort, along with helping in maintaining the organization’s reputation, as well. A highly reliable and advanced SMTP server makes life a lot simpler for the internal IT security teams, as well.