Send Test Mail Error

[jackgw]

I'm trying to get the Send Test Mail feature working.

I've added the following line to .env.local as specified, with newly generated SES SMTP credentials and the correct region:

MAILER_DSN=ses+smtp://<SMTP username>:<SMTP password>@default?region=us-west-2

However, when trying to send an email, I get the following message (email addresses have been removed afterwards for privacy):

---

The MAILER_DSN is configured correctly according to the Symfony Docs.

The SMTP credentials have been generated in accordance with the SES Docs.

The email address used to send from/to is a verified identity within SES.

So I'm not sure what else may be the problem. Is there any way to debug this error, or any additional documentation on the setup for the test mail feature?