Postfix

If you use Postfix on your server you have to change  config > mail.php

// ‘driver’ => ‘smtp’,
‘driver’ => ‘sendmail’,

Install Postfix: http://www.codechewing.com/library/set-up-postfix-on-ubuntu-server/

https://help.ubuntu.com/14.04/serverguide/postfix.html

useful:

https://www.linode.com/docs/email/postfix/email-with-postfix-dovecot-and-mysql

Configure Postfix to Use Gmail SMTP on Ubuntu https://rtcamp.com/tutorials/linux/ubuntu-postfix-gmail-smtp/

Smtp

http://www.havetheknowhow.com/Configure-the-server/Install-ssmtp.html

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