Dar Tamesna Voyages: customers no longer receive booking confirmation emails

Dar Tamesna Voyages (a fictional agency for stays in the South: riads, bivouacs, tours) sells online on www.tamesna-voyages.ma. Each booking drops a message into the SQS queue tamesna-confirmations; the Lambda function tamesna-envoi-confirmations reads it and sends the confirmation email with Amazon SES.

Yesterday around 17:00, a developer changed the function so that it adds the room number to the email, read from the bookings RDS database (in a private subnet of the VPC). Since then, no email has gone out. Bookings are recorded correctly, but customers are calling to find out whether their stay is confirmed. It is not a sales outage: priority P3, to be fixed this morning.

You are a cloud engineer, with the AWS CLI v2 (region eu-west-1).