I searched my mails for couple of words including instance ID, result is negative. No email in spam folder in last one month.
Subject: Amazon EC2 Maintenance - Instance Maintenance Account: NNNNNNNNNN
Dear Amazon EC2 Customer,
One or more of your Amazon EC2 instances have been scheduled for maintenance. The maintenance will result in a reset of the network connection for your instance(s). The network reset will cause all current connections to your instance(s) to be dropped. The network reset will take less than 1 second to complete. Once complete your instance(s) network connectivity will be restored. The instance(s) will have their network connections reset during the time window listed below.
You can avoid having your network connection reset at the specified time by rebooting your instance(s) prior to the maintenance window. To manage an instance reboot yourself you can issue an EC2 instance reboot command. This can be done easily from the AWS Management Console at http://console.aws.amazon.com by first selecting your instance and then choosing ‘Reboot’ from the ‘Instance Actions’ drop down box.