nullmailer configuration

To send e.g. status mails from raspiBackup as root, nullmailer can be used.

The following variables are used in the description (provider is Hetzner):

• eMail Domain: MYDOMAIN (e.g. dummy.de)
• Hostname of the server: HOSTNAME (e.g. myserver)
• smtp Hostname to deliver emails: SMTP_PROVIDER_HOST (e.g. mail.your-server.de)
• Userid to send emails: SMTP_INPUT_USERNAME
• Password to send emails: SMTP_INPUT_PASSWORD

Changes or additions:

• Installation of mail: sudo apt install mailutils -y
• /etc/nullmailer/remotes:

  SMTP_PROVIDER_HOST smtp --auth-login --user=SMTP_INPUT_USER --pass=SMTP_INPUT_PASSWORD --ssl
  

If the host name is not a valid host name at the e-mail provider, the following steps are necessary:

• Install and configure Nullmailer Rewrite Wrapper. Set NULLMAILER_USER=SMTP_INPUT_USER and NULL_MAILER_HOST=MYDOMAIN in "sendmail".
• sudo chown 700 /usr/sbin/sendmail