SES: SMTP user credentials

SMTP credentials vs. IAM Access Keys

If it looks like an IAM credential, walks like an IAM credential, and quacks like an IAM credential... well, this time it's actually an SMTP credential. 

When you create SMTP user credentials in SES, be aware that although they look like IAM access and secret keys - they are not!

They have the same format, and will appear in the IAM console as one of the access keys for the generated SMTP user - but they have a hidden purpose. These are the only keys that can authenticate that user for SMTP - generating a new access/secret key pair in the IAM console will not authenticate correctly.

To actually regenerate the SMTP keys, you have to use the "Manage SMTP credentials" area in the SES console, where you can create new ones (the button that goes off to the IAM console isn't helpful here).