Sending alerts to MS Teams from AWS

Hi, the commonly used methods are using a Webhook or Email as you've tried. I'm not aware of any other way to integrate SNS with MS Teams but as you mentioned you're not receiving the subscription email it sounds like you should spend some time investigating why that is happening rather than trying to pivot to another method.

You can also use AWS Chatbot with Teams now. -> https://aws.amazon.com/blogs/aws/aws-chatbot-now-integrates-with-microsoft-teams/

Or you write your own Lambda to send alerts trough webhook to teams -> there is also a nice npm package for adaptive cards available: https://www.npmjs.com/package/adaptivecards