Testing Rails ActionMailer and AWS SES

I added two verified email addresses to AWS SES so that I could send emails from/to them while in the SES Sandbox.

UserMailer

class UserMailer < ApplicationMailer
  default from: '[email protected]'

  def welcome_email
    mail(to: '[email protected]', subject: 'Welcome to My Awesome Site')
  end
end

ActionMailer config

config.action_mailer.smtp_settings = {
  address: 'email-smtp.eu-west-1.amazonaws.com',
  port:	25, # or 465 or 587
  enable_starttls_auto: <boolean>,
  tls: <boolean>, 
  ssl: <boolean>, 
  user_name: '<username>',
  password: '<password>'
}

Test command

$ rails r "UserMailer.with({}).welcome_email.deliver_now"

Result summary

Ports 25 and 587 require enable_starttls_auto to be set to true, and for tls and ssl to be set to false.

Port 465 ignores enable_starttls_auto and requires either tls or ssl to be set to true.

This relates to the Connecting to the Amazon SES SMTP Endpoint documentation which says that SES supports STARTTLS on ports 25, 587 and 2587, and supports TLS on ports 465 and 2465.

Results

Port	Enable STARTTLS Auto	TLS	SSL	Outcome
25	True	True	True	`OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=SSLv2/v3 read server hello A: unknown protocol`
25	True	True	False	`OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=SSLv2/v3 read server hello A: unknown protocol`
25	True	False	True	`OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=SSLv2/v3 read server hello A: unknown protocol`
25	True	False	False	Email sent correctly
25	False	False	False	`Net::SMTPAuthenticationError: 530 Must issue a STARTTLS command first`
25	False	True	True	`OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=SSLv2/v3 read server hello A: unknown protocol`
25	False	True	False	`OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=SSLv2/v3 read server hello A: unknown protocol`
25	False	False	True	`OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=SSLv2/v3 read server hello A: unknown protocol`
465	True	True	True	Email sent correctly
465	True	True	False	Email sent correctly
465	True	False	True	Email sent correctly
465	True	False	False	`Net::ReadTimeout: Net::ReadTimeout`
465	False	False	False	`Net::ReadTimeout: Net::ReadTimeout`
465	False	True	True	Email sent correctly
465	False	True	False	Email sent correctly
465	False	False	True	Email sent correctly
587	True	True	True	`OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=SSLv2/v3 read server hello A: unknown protocol`
587	True	True	False	`OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=SSLv2/v3 read server hello A: unknown protocol`
587	True	False	True	`OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=SSLv2/v3 read server hello A: unknown protocol`
587	True	False	False	Email sent correctly
587	False	False	False	`Net::SMTPAuthenticationError: 530 Must issue a STARTTLS command first`
587	False	True	True	`OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=SSLv2/v3 read server hello A: unknown protocol`
587	False	True	False	`OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=SSLv2/v3 read server hello A: unknown protocol`
587	False	False	True	`OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=SSLv2/v3 read server hello A: unknown protocol`