Port 25 is blocked on AWS

Question

I am completely new in AWS and I want to know about port 25 to send SMTP mail. My organisation is using one SMTP relay server which is having only one port 25, no any other port is available. I have an application (written in flask) which i will deploy on AWS and will use it to send SMTP mail using my organisation's server to outlook. Now, i want to know whether port 25 is blocked or not and can it be used in this scenario or not.

Thanks in advance.

Answer 1

This is blocked on purpose by Amazon.

If the email provider supports another port you're advised to use this, however it seems for your use case you're limited.

In this case you will need to follow the instructions that are available on the How do I remove the restriction on port 25 from my EC2 instance? page. This will require you to fill in this form specifying your business case for why it needs to be unblocked.