Enhancement Autoconfigure mail in docker-compose production

[Jesterboxboy]

It would be very comfortable if the functionality to send recovery and signup mails via smarthost would work out of the box with docker compose.

Tested Steps to make it work:

• Add Environment Variables to env file for Docker Compose

   FROM_MAIL=Pantheon<pantheon@domain.test>`
   SMTP_HOST=mail.domain.test:587
   SMTP_USER=user@domain.test
   SMTP_PASS=password
   SMTP_TLS=YES
   SMTP_STARTTLS=YES

• apk add ssmtp in Frey container

• Add configuration for ssmtp to /etc/ssmtp/ssmtp.conf filled with env variables

  # cat /etc/ssmtp/ssmtp.conf 
  # Config file for sSMTP sendmail 
  #
  # The person who gets all mail for userids < 1000
  # Make this empty to disable rewriting.
  root=

  # The place where the mail goes. The actual machine name is required no
  # MX records are consulted. Commonly mailhosts are named mail.domain.com
  mailhub=SMTP_HOST

  # Where will the mail seem to come from?
  rewriteDomain=

  # The full hostname
  hostname=pantheon

  # Are users allowed to set their own From: address?
  # YES - Allow the user to specify their own From: address
  # NO - Use the system generated From: address
  FromLineOverride=YES

  AuthUser=SMTP_USER
  AuthPass=SMTP_PASS
  UseTLS=SMTP_TLS
  UseSTARTTLS=SMTP_STARTTLS

• Add FROM Header i.e. in send function in Mailer class in Frey/src/helper/Mailer.php
  protected function _send(string $to, string $subject, string $message, array

     $additionalHeaders, string $additionalParams)
    {
        $boundary = md5(uniqid() . microtime());
        $additionalHeaders['Content-Type'] = 'multipart/alternative; boundary="' . $boundary .      '"';
        $additionalHeaders['From'] = SMTP_FROM;

[Jesterboxboy]

I will try to make it work in a branch, and create a PR request

[ctizen]

@Jesterboxboy I added a separate container with email agent, I think it should resolve this issue. Updated the readme with infomation about how to make it work.