sending emails from a website [duplicate]

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• How to send an email using PHP? 13 answers

I'm fairly new to web design, and am currently working on my first big web project, I've hit a road block however as I need to send an email from the site, based on input. I can use PHP forms to collect input, but can't figure out what to use to actually send the email. so the question: What is the best method for sending emails server side, and how do I do it.