What Is an SMTP Server ? Part 2

What is an SMTP Server?

Part 1

Simple Mail Transfer Protocol or popularly known as SMTP is a protocol that enables you to send and receive emails and relay between email senders (ISPs) and receivers. While SMTP is responsible for this process, the entire process and framework are made possible by the server, known as an email or simple mail transfer server.

Here is the catch, when you send your emails, the server receives them, and decides which server to send your email to, it relays the servers and finally gets it delivered. Let me bring this home, when you write your beautiful content and hit the send button on your email, it is sent to a server called SMTP server. The server picks it up and relays it with other servers until it drops it where it is supposed to be.

So in your email list of 10,000 contacts, you may have 5000 Gmail users, 2000 Hotmail users, and 3000 yahoo mail users. When you send out your campaigns, your SMTP server picks them out and distributes them to the various servers, this process is called a relay, and then the mails are downloaded by your servers and placed in your inbox.

SMTP picks up your email, sends it to the server, the server relays it, and sends it to the receiver’s mail. It is as simple as this, everything is sorted out before you can even notice.

Why is an SMTP server important?

Here are the reasons why you should use an SMTP server and why it is important for your business.

  • Without an SMTP server, your emails will not reach their destination

The thing is this, with the behavior-triggered emails, you are invariably sending out a string of codes which the server will pick up, process, and pass on the message to the relevant servers for onward delivery. Without a server, this all-important process is vitiated and when this happens, your messages are lost in transition, they will never reach their destination.

This is not what you want, this is never the reason you have chosen to leave the traditional email sending outfits for a more organized and robust system, so ensure you are connected to a server to avoid this headache. Therefore, to have a high level of deliverability your server must be connected to make this work.

  • You bypass restrictions set by email providers

If you want to take on email campaigns, which is an essential aspect of your email marketing strategy, the traditional mail carriers will do you little or no good at all. The first block is the restrictions, on Yahoo Mail, for instance, you are restricted to 1000 emails per hour, an attempt to surpass this, will either leave your emails labeled spam or not delivered at all.

This is not all, when you send the same email to bulk Emails before your client labels them spam, your provider automatically places them in the spam folder, especially if there are certain spam trigger words involved. And this will take away the goal at hand, which is to reach more clients and have your emails read.

  • Security of your emails

Unlike SMTP servers, the regular servers used by traditional email providers are shared among users, and this comes with no dedicated IPs. The reality is that your emails can end up being relayed by an IP that is used by a spammer, your emails will end up not being correctly delivered.

How then does an SMTP server work?

I will explain the workings of the SMTP server in four simple and easy to understand steps below:

Step 1: Sending the email

You start by sending your email after the content is correctly written and the dots are carefully dotted. You push it out from your webmail or any mail service of your choice.

Step 2: the server gets the mail

Once your mail is shipped out of your draft list, it lands at the door of the server. What happens next is quite complex and simple at the same time, your email is checked, not the content of the email but the details, such as the sender address, receiver’s address, and others.

The purpose of this is to decipher what goes out and to which server they will go, after this is done step 3 is activated.

Step 3: Delivery of the mail:

Delivery is what follows next, if the receiver is using the same server as the sender it is one less headache for the sender as the mail is sent automatically, without the need for third-party delivery agents. If the receiver is not using the same domain or server, the mail is handed over to an incoming server for onward transmission.

This process is called a relay, and after this is done, the mail is sent out. The question then will be, what happens if the server of the receiver is down?

This is what plays out, the SMTP host will drop the email with a backup server, and the sending process will be repeated periodically, and sometimes it is queued. When it fails, after several attempts, it is returned to the sender.

Step 4: where POP and IMAP comes in

After the email is a relay and the right server for delivery is determined, POP 3 (Post Office Protocol) and IMAP (Internet Message Access Protocol) are responsible for the final delivery role. These protocols will pick the email from the server and have it placed in the receiver’s inbox.

Right there, it is available for reading, and boom, the job is done.


The workings of the SMTP server are important for the marketing professional who seeks to hit gold with his email marketing campaigns. Knowing what goes behind the scene, will help to put your entire campaign in one breath. And since you seek to achieve success on this end, education of this kind will do more than good.

Now that you know what an SMTP server is and just how it works. Giving your email marketing campaigns the facelift it deserves, will be a guaranteed way to milk the industry of the cash flow that seems to have no end. Your success along this path is my desire.

Download my company’s latest eBook on SMTP servers

Digital & Social Articles on Business 2 Community

Author: Aabhas Vijay

View full profile ›


Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.