You might be looking to send emails connecting to Amazon SES SMTP endpoints. But, if you run into Authentication Errors and you want to test the credentials, you can try testing openssl following the steps here.
If you want, one simple way to test the validity of these SMTP credentials is, to use this website https://www.smtper.net/. You need to pass SMTP host SMTP access key ID, secret access key ID and from and to email addresses.
Also, you want to ensure that you are using the SMTP credentials generated from the SES console. If not, you may want to convert the regular IAM user secret access key to SMTP password following instructions here. While using this code from the documentation, make sure you run the code using Python3, for example : python3 <codefile.py> –secret <secret access key ID> –region <region>.