Introduction

Sending emails from Amazon EC2 involves specific configurations and steps. This process can vary slightly depending on the email delivery service you choose. In this article, we'll explore how to send emails from an EC2 instance using different methods, discuss the limitations imposed by AWS, and provide technical explanations with examples.

Prerequisites

Before diving into the technicalities, ensure you have the following:

1. An active AWS account.
2. An EC2 instance running.
3. Basic understanding of EC2 and SMTP (Simple Mail Transfer Protocol).
4. An email delivery service account (such as Amazon Simple Email Service, SendGrid, or others).

AWS EC2 Email Sending Constraints

When using EC2, it's essential to be aware of AWS's restrictions on sending emails:

• Port 25 is typically throttled. AWS restricts traffic over port 25 (SMTP) to prevent spamming. It's recommended to use ports 587 or 465.
• Soft Limits on Sending Rates. AWS imposes limits on the number of emails you can send per second and per day to maintain quality and avoid spamming.
• Email Service Usage Suggested. Using AWS SES (Simple Email Service) or other SMTP service providers is suggested for better deliverability and management.

Methods to Send Emails from EC2

1. Using Amazon Simple Email Service (SES)

Amazon SES is a cost-effective, flexible, and scalable email service that enables developers to send mail from within applications.

Steps to Configure and Send Emails Using SES:

1. Verify Domain/Email:
   • Sign in to the AWS SES console.
   • Verify your domain or email address through the SES console.
2. Configure SMTP Credentials:
   • Create SMTP credentials in the AWS SES console.
   • Save the SMTP username and password for later use.
3. Setup EC2 Instance:
   • Install an email client on your EC2 instance (e.g., postfix, sendmail).
   • Update the mail configuration files with the SES SMTP server details.
4. Send Email:
   • Use a script to send an email via AWS SES. Below is an example using Python's smtplib :
   • Sign up with a third-party email provider like SendGrid.
   • Note down the SMTP configurations provided.
   • Install necessary SMTP libraries or email clients (similar to SES setup).
   • Use the SMTP configurations to send emails as illustrated for SES.