AppRunner Network Connectivity and Security Group to work with resend (email service)

Thank you for your answer, I read posts you linked here, I understand that Port 25 no longer can be used . So, switched to SMTP ,

Here is my nodemailer settings:

const transporter = nodemailer.createTransport({
            host: process.env.EMAIL_HOST || 'smtp.resend.com',
            secureConnection: false, // TLS requires secureConnection to be false

            port: process.env.EMAIL_PORT || 2587,
            auth: {
              user: process.env.EMAIL_TRANSPORTER_USER,
              pass: process.env.EMAIL_TRANSPORTER_PASSWORD,
            },
            tls: {
              ciphers:'SSLv3'
            },
});

Tried all ports posted on resend site for SMTP: Send emails using SMTP instead of the REST API.

See documentation for more information.

Host smtp.resend.com

Port 465 For encrypted/TLS connections use 2465, 487, 2587 and still getting errors, see bellow

`Here is my logs:
2025-02-08T18:40:32.605-06:00 Error: Connection timeout 2025-02-08T18:40:32.605-06:00 at SMTPConnection._formatError (/app/node_modules/nodemailer/lib/smtp-connection/index.js:809:19) 2025-02-08T18:40:32.605-06:00 at SMTPConnection._onError (/app/node_modules/nodemailer/lib/smtp-connection/index.js:795:20) 2025-02-08T18:40:32.605-06:00 at Timeout.<anonymous> (/app/node_modules/nodemailer/lib/smtp-connection/index.js:237:22) 2025-02-08T18:40:32.605-06:00 at listOnTimeout (node:internal/timers:581:17) 2025-02-08T18:40:32.605-06:00 at process.processTimers (node:internal/ti

And one more notes, I tested all ports on local and they works for sending emails, so there is something blocking on AWS

Is your AppRunner connected to a custom VPC? In that case, you will not be able to access external services from AppRunner unless you set up a NAT Gateway. https://aws.amazon.com/jp/blogs/containers/deep-dive-on-aws-app-runner-vpc-networking/