We have encountered an issue when configuring AWS SES as the SMTP provider in Mautic. The SMTP password (AWS Secret Access Key) is saved encoded in the local.php file, but it seems that Mautic is sending the encoded password during authentication, causing an error when trying to connect to AWS SES.

A temporary workaround is to use an AWS Secret Access Key without special characters, but this is not an ideal solution for long-term security.