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SMTP or API | Which one would you choose to send emails to?

What’s your choice? Option to select gives facilities the power to differentiate and the ability to judge. 

In general use, there are 2 choices and each has its advantages and limitations. A platform-skeptical SMTP is the utmost public one. This is created on SMTP and at times is the common option provided. On the other hand,  Web APIs are considered a notch higher than the simple mail transfer protocol process since it has more use cases and have over a very short period gained immense popularity.

To know more about these two email options; we have to dig deeper.

The process of sending emails usually involves one of the two protocols; Simple mail transfer protocol [email server] or HTTP [web-server]. Both the options have unique offerings and benefits for us to select.

Every email sent by an email server is based on the standards and guidelines of the SMTP- what matters here is whether you as the email agent would like to monitor and regulates these processes on your own by supervising your own Simple mail transfer protocol interface, or use the API. Both approaches bring with them their advantages and disadvantages.

Let’s take a look to first understand what is SMTP and API are?

Define SMTP [Simple mail transfer protocol] is the inventive protocol for sending emails and, to date, holds the same standard. It exists for more than 4 decades as the guiding standard protocol for each email communication and is the de facto procedure to date for receiving and sending emails from outside your system.

What does it do? SMTP requires the procedures, actions, and workings of an e-mail, and how it can be mailed in one format and interpreted by any other email server in a completely platform-agnostic way. It is a boon for developers worldwide.

What does it do? It permits user apps to connect and use functions accessible and facilitated by email service providers and marketers for email management. API is a universal web protocol for diverse kinds of data and is primarily used for email.

The determining feature will customarily be some unique arrangement of accessibility for your use case, availability/ expense of coding/hardware resources, and the relative priority for your business of things like sending speed and ease of migration.

One will find hindrances in both the approaches–some might consider API has better usability and hence preferred by many developers and email marketers whereas using SMTP allows us a larger span of use cases.

Decoding SMTP and API functionalities; a Digital journey

As stated above, SMTP is a standard protocol that permits your system or mobile email app to create emails and then send them to the server whereas API is the path or medium to communicate to other code. HandySends sends email either using SMTP (which happens when the user sends mail directly from their mobile email app) or through API (which has to be integrated into the form of a code in your emailing platform so that the communication begins).

SMTP makes the complete process of sending emails very simple. How? Whenever an external client wants to send an email using the SMTP server, the SMTP server connects with the transmission control protocol, and the process of connecting to that particular port is initialized. For example, the store and forward method are used if it is an internal communication happening within inter-organizational, and the end-to-end method is implemented while the communication is outside the organization. 

API behaves like an options catalog. As soon as something is selected, the packaging starts. API, however, provides the developer with options that he can select from and when it is selected, it then makes use of that program. 

How are they different–a glimpse

Simple Mail Transfer protocol HyperText Transfer Protocol
Platform independent protocolSlightly complicated
Both ways communicate using multiple back-and-forths and are time-consuming fractionally since Using SMPT, the email must have its DNS and required authentication, the mail is sent post verification The Web API enables mailing faster since they don’t conduct back-and-forth as SMTP
Best for casual mail sending campaigns API is marketers and developers first choice 
Integration & Usage Higher than API
Requires integration with a CRM system or mail client
Preferred by App developers and email marketers 
Set up procedure and trouble-shooting is easyAllows automating your transactions and track metrics

As explained above Simple mail transfer protocol is a standard protocol that our mail sender uses to send mail to the server. Now one important thing to understand here is emailing is communication that happens between a client and a server. Initiation starts when the mail is sent, the transmission control protocol actions it with a specific port. Here the user agent sends a varying piece of information that is authenticated and verified by the server. The server and the TCP communicate using SMTP, a simple mail transfer protocol supported by response codes. If the authentication and verification are as standard, the email sends by the user agent is transmitted to the receiving standard protocol server. Now both the user agent and the recipient server have related conversations. The final output will vary depending on the IMAP or POP3 protocol of the recipient.

Here the decision takes place, whether the mail will be sent, bounced /congested, or returned.


How API works

Web API is an interface where communication happens using web-specific protocols primarily HTTP, which is a universal protocol that means not only email specific but all kinds of data. This is used when client-server computing such as web applications, mobile apps, or IoT uses HTTP to send email data. It is the developers who integrate email functionalities into a function and convert them to a HyperText transfer protocol API, using its benefits it offers other functions other than sending emails, those which complement the associated routine jobs.

As you interact with any of the software applications while using the internet, you are unknowingly enjoying the protocol of the web, HTTP. However, as you browse a webpage–you are completely making HTTP communication for sending and receiving information. The key benefit of selecting HTTP as your preferred protocol for sending email is, it is less probable to be blocked or bounced by firewalls–which most likely are the case while using SMTP.



If asked to choose one of the two, the answer would be varying for each one of us. Technical experts would prefer working with API and it gives you a clear option to tailor-make and amends the codes/set up need-based. A marketing professional would vote upfront for API and the set-up it offers provides value-added benefits to initiate automation processes, tracking, and access various delivery metrics that go a long way while you enhance and augment your email content.

If you are an email sender, the most curious question in your mind will be how is your email performing? Is it able to hit the target? Mail SMTP comes handy in this regard and apart from offering simple and easy solution-it offers ease in executing all elementary jobs.

SMTP works on the back-and-forth communication processes before sending an email to the recipient whereas API is an undeviating window and using API accelerates the message sending process. Though the final objective of both SMTP and Email API is to obtain higher deliverability scores–the point of difference is their methodology to achieve and maintain their set target score.

A quicker grasp of the above 

SMTP is a suitable choice for simpler use casesOnly those who understand and are skill coder can set up and execute, In case the codes have error-it becomes a pain point
SMTP is stable as compared to APIRequires constant updating and amendments to stay updated with the dynamic changes and demand
SMTP offers fine-grained control and additional redundancy assurances.Offers enhanced security and is allowed by most firewalls 
SMTP offers the finest granularity in terms of controlAPI offers flexibility and fluidity 
You do not depend on a third-party intermediaryDelivers faster, reduces the potential steps for failure when sending an email
Create a message and send it to the server directly–less dependencyHigher customization, the lower option of failure

Who wins the battle? SMTP, a smart email standard protocol seamlessly connects with applications such as CRM or API, the developer’s choice since they master their application.

In reality, the choice on whether to use SMTP or API is completely different and dependent on your needs as well as the capability of the platform you are using to send these emails.

Pick your favorite.

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