Many PHP developers need to send email from their code. The only PHP function that supports this directly is mail(). However, it does not provide any assistance for making use of popular features such as encryption, authentication, HTML messages, and attachments.
Formatting email correctly is surprisingly difficult. There are myriad overlapping (and conflicting) standards, requiring tight adherence to horribly complicated formatting and encoding rules – the vast majority of code that you'll find online that uses the mail() function directly is just plain wrong, if not unsafe!
The PHP mail() function usually sends via a local mail server, typically fronted by a sendmail binary on Linux, BSD, and macOS platforms, however, Windows usually doesn't include a local mail server; PHPMailer's integrated SMTP client allows email sending on all platforms without needing a local mail server. Be aware though, that the mail() function should be avoided when possible; it's both faster and safer to use SMTP to localhost.
Please watch the Video below to see explanation about using it: