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SMTP Service Crash Course

Wondering how your emails move across networks and reach the intended recipient? This is made possible through SMTP. Let’s take a crash course on SMTP.

What is SMTP?

Simple Mail Transfer Protocol (SMTP) is a part of the TCP/IP protocol. It uses a method called “store and forward” to move your email on and across networks. The message is sent to the mail server by the mail client using SMTP. This mail server then relays the message to the correct mail receiving server through SMTP.

What is Email Relay?

SMTP is the protocol used for delivering emails. Email relay is the process of transferring email from one email server to another.

For example, if you work for a company X and you want to send an email to someone in company Y, you will connect to your company’s SMTP server which will then relay your email to company Y’s server. This process is called an email relay or SMTP relay.

If you wanted to send an email to someone having the same domain as yours, then there would be no second server. Such type of email sending is not relaying as only one server is involved.

What is an SMTP Relay Service?

An SMTP relay service (SMTP provider) is a service that allows you to send and deliver bulk emails by routing the emails through a third party. This helps senders in sending their emails through SMTP. This is useful when one is sending:

● Transactional emails

● Bulk emails (especially from CBT Mass Email Sender)

● Newsletters

● Marketing emails

Internet Service Providers set up a limit to the number of SMTP relays it can conduct per day. This is done so that the recipients are safe from spam. This can however affect business organizations sending transactional or marketing emails to their customers. An SMTP relay provider can help them deliver a large number of emails without being labeled as spam.

When Should I Use SMTP Service?

You might be wondering when should one use SMTP relay service? The following conditions might be a good time to use it:

● You have built an app (web or mobile). Now, in order to send emails from that app or website, you can use an SMTP relay service.

● You want to increase your email deliverability.

● You need to send emails from different hardware devices.

● You want to send bulk emails without being labeled as spam by the internet service provider.

Why Should I Use SMTP Service?

Sending emails is pretty straightforward if you send a few emails every day. In case you’re running a business and sending a large number of emails or running email marketing campaigns, you might face some problems in email delivery. These can be:

● Email ending up in the spam folder

● Email not getting delivered at all

● Low delivery rate

If you are sending these marketing emails from your primary email server, then there's a high chance that you will face these issues as you reach your ISP's specified daily email sending limit. Making sure that your emails are delivered properly and do not end up in the spam folder is both time-consuming and expensive. Using an SMTP provider is therefore a good decision for handling your emails efficiently and ensuring high deliverability.

How Does Smtp Service Work?

If you are sending an email using SMTP, this is what happens behind the scenes:

● The moment you hit ‘send’, the email client (Gmail, Yahoo, etc) sends a message to your server’s Mail Submission Agent (MSA).

● The MSA checks for any errors.

● If the recipient is from the same server, the message is simply delivered. No relay happens in this case.

● This is a very rare case because most of the recipients are on different servers. Even famous email providers like Gmail have several servers.

● When the recipient is on some other server, the MTA checks the MX record of the recipient’s domain.

● Once a match has been found, the message is transmitted to another MTA.

● The message is moved between two or more MTAs depending upon the destination and number of recipients.

● After all this moving, the mail is finally received by the MDA. MDA or Mail Delivery Agent is software stored on the recipient's device. It receives the message, converts it into the proper format, and passes it to MUA.

● MUA then displays the message to the recipient.

Who Should Use The SMTP Service?

If you’re an individual who sends business emails rarely, then opting for an SMTP provider service might not be a good choice for you. Even if you send 10-20 emails a day, a normal server would not mark you as spam and you would be able to send emails easily.

If you are a new startup or an existing business that is planning on engaging existing customers or getting new customers through marketing emails, newsletters, or promotions, then you should opt for an SMTP service provider.

If your business requires sending hundreds of emails in a day, be it transactional or marketing, you should use SMTP relay service because there is always a chance that the ISP might flag your IP as spam and your emails might not reach the inbox of the desired recipient.

In short, you should use SMTP relay service if:

● You send out hundreds of emails daily

● You are sending marketing emails

● You provide email transaction services

● You engage with your clients regularly through emails.

● Your emails are ending up in the spam folder

● You are unable to get your emails delivered properly

So evaluate your needs, analyze your email sending volume, check your email engagement, and then decide if you need an SMTP relay service or not. Several third-party software out there can provide you with SMTP relay service.

SMTP services are a great way for new startups and existing businesses to scale their business and to meet their communication needs with ease and without any hindrance. Third-party software provides an easy to use solution for those who do not want to get into details of how things are supposed to work.