I suspect the problem is that I simply can’t find a working example of how to configure Amazon SES config for Elixir / Phoenix.

The problem seems to be cacerts: :undefined.

export SES_SMTP_SERVER=email-smtp.us-west-1.amazonaws.com
export SES_SMTP_PORT=465
export SES_SMTP_USERNAME=redacted
export SES_SMTP_PASSWORD=redacted

Here’s my config/prod.exs:

config :my_app, MyApp.Mailer,
  adapter: Bamboo.SMTPAdapter,
  server: System.get_env("SES_SMTP_SERVER") || "email-smtp.us-east-1.amazonaws.com",
  port: String.to_integer(System.get_env("SES_SMTP_PORT") || "587"),
  username: System.get_env("SES_SMTP_USERNAME"),
  password: System.get_env("SES_SMTP_PASSWORD"),
  tls: :always,
  tls_cacertfile: "/etc/ssl/certs/ca-certificates.crt",
  ssl: true,
  retries: 1,
  ssl_options: [
    verify: :verify_peer,
    cacertfile: "/etc/ssl/certs/ca-certificates.crt"
  ]

Here’s the error that I’m getting when I try to send email:

Failed to send email.
Reason: {:network_failure, ~c"54.176.126.9", {:error, {:options, :incompatible, [verify: :verify_peer, cacerts: :undefined]}}}

It sounds like it can’t find the SSL / TLS (?) certificate file. I’ve run apt-get install ca-certificates to no avail, same error message.

I’ve looked up the docs for Bamboo.SMTPAdapter [1] but there’s no hint on how to specify the SSL certificate.

Has anyone successfully sent email from Phoenix in production?

For context, I encountered a similar error when trying to send email via Gmail with Elixir / Phoenix: Phoenix / Elixir: Sending email via Gmail certificate error

Update: I started with Swoosh, switched to Bamboo, neither work, so my question is: what is the underlying problem?

[1] https://hexdocs.pm/bamboo_smtp/Bamboo.SMTPAdapter.html