prerequisite for external smtp server
Currently my linode server is hosting nodejs web app which is have multiple user and have their own email. By using external smtp server such as gmail and etc to let them sending email..
My problem is i didn't know what should i install into my running server in order to make my website's email functioning.. I read this that i need to setup postfix in my server but it seems like only work on 1 emails..
In my website script, i used phpmailer..
If you've already got email working through GMail, then you can certainly use the phpMailer class to have your website scripts use SMTP authentication to your gmail account to send out email messages.
This should only require that your website scripts that send email are updated to use the phpMailer class and SMTP authentication, and that the phpMailer class is present and accessible by those scripts.
On the other hand, if you're referring to setting up a mailserver on a Linode, you can find a wealth of information on this helpful support article