SMTP Server: The Backbone of Email Sending

What is an SMTP Server?

SMTP, or Simple Mail Transfer Protocol, is a protocol used to send emails across the Internet. An SMTP server is a mail server that uses the SMTP protocol to handle the sending, receiving, and relaying of email messages. It acts as a digital postman, ensuring that your emails are correctly routed and delivered to their intended recipients.

How Does an SMTP Server Work?

SMTP servers work by processing email messages and directing them to the appropriate recipient’s mail server. Here’s a simplified overview of the process:


When you send an email, your email client (like Gmail, Outlook, or Yahoo Mail) connects to your SMTP server.


The SMTP server processes the email, verifying the sender’s details and preparing the message for delivery.


The SMTP server contacts the recipient’s mail server using DNS (Domain Name System) to find the correct destination. It transfers the email to the recipient’s SMTP server.


The recipient’s SMTP server receives the email and stores it until the recipient retrieves it using an email client via POP3 or IMAP.

Benefits of SMTP Servers


SMTP is a well-established and reliable protocol for sending emails, ensuring that messages are delivered accurately.


SMTP is compatible with a wide range of email clients and servers, making it a versatile choice for email communication.


SMTP servers can be configured to automate email sending for various applications, including newsletters, alerts, and notifications.

Asynchronous Communication

Unlike phone calls or instant messaging, emails do not require both parties to be available at the same time, allowing for more flexible communication.

Protocol Standardization

As an open standard, SMTP ensures interoperability between different email systems and services.

FAQ - Frequently Asked Questions

What is transcription process?
Each audio file is tested, transcoded, and then transcribed using the Whisper model from the OpenAI API.
How long does it take to get a transcript?
The processing time for your transcript will depend on the length of the audio file. Typically, shorter voice messages can be transcribed quickly using OpenAI speech-to-text API.
What are the maximum file size for transcription?
Note that our transcription service has a file size limit of 20 MB.
What is the maximum duration you can transcribe?

We currently have a file size limit of 20MB. Given that most voice messages are encoded with a constant bitrate and a single channel (mono, no stereo), we can calculate the maximum duration of a file using the following equation:

Duration ( seconds ) = File Size ( bits ) Bitrate ( bits/second )

Applying this equation to our 20MB limit and a bitrate of 64 kbps (commonly used by the iPhone recorder app), we arrive at a maximum duration of approximately 43 minutes and 41 seconds. To easily calculate durations for different file sizes and bitrates, you can use our audio duration calculator.

Do I need to transform the audio before sending it to my email address?
No, this is not necessary. will automatically transcode your audio file upon receipt into the format expected by the OpenAI API.
Can ChatGPT transcribe audio to text?
Yes, ChatGPT can transcribe audio to text, but there are more specialized AI models specifically designed for this task, such as Whisper. Whisper is a state-of-the-art transcription tool that offers higher accuracy and efficiency in converting audio to text. If you're looking for the best results in audio transcription, Whisper is the ideal choice.
Why transcription over email?
Our email-based automatic transcription service is designed to break down barriers and provide universal access to voice message transcription. By leveraging email as our input and delivery method, we're making it easy to automate and integrate with existing platforms. Since email is an established communication method, it's likely to persist, offering longevity.