SMTP stands for Simple Mail Transfer Protocol. It's used for sending email messages between servers or from a mail client to a mail server. SMTP is a part of the application layer of the TCP/IP protocol suite and it provides a standard way of transferring email messages between different email systems.

Send mail  with attached php PHPMailer SMTP Sendinblue 

We see first how to send mail using PHPMailer.

We can use 2 types of ports (587,465)

SMTP 587

SMTPS encrypted email transmissions 465

Create an HTML form for sending mail. I'm not wasting time. You will make it.

<?php 

$contact_no=$_POST['cn'];
$address=$_POST['add'];
$date_of_birth=$_POST['dob'];
$experience=$_POST['ex'];
$education_qualification=$_POST['eq'];
$email=$_POST['email'];
$full_name=$_POST['fn'];

use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;
require_once "PHPMailer/src/PHPMailer.php";
$folder='uploads/';
if (isset($_POST['submit']))
{
    $contact_no=$_POST['cn'];
    $address=$_POST['add'];
    $date_of_birth=$_POST['dob'];
    $experience=$_POST['ex'];
    $education_qualification=$_POST['eq'];
    $email=$_POST['email'];
    $full_name=$_POST['fn'];
    if($_FILES['upcv']['size']>0)
    {
        $file_img_profile = basename($_FILES['upcv']['name']);                
        $ext = pathinfo($file_img_profile, PATHINFO_EXTENSION);                
        $allow=('pdf,docx,doc');                
        $allow=explode(',',$allow);                
        foreach($allow as $key=>$extm)                
        {                    
            if($ext===$extm)                    
            {
                $full_path_imagess1 = 'cn-766482_'.time().$file_img_profile;                        
                $full_path_imagess2 = $folder.'cn-766482_'.time().$file_img_profile;                        
                move_uploaded_file($_FILES['upcv']['tmp_name'] ,$full_path_imagess2 );
                $mail = new PHPMailer(true);
                $mail->setFrom($email,$full_name);
                $mail->addAddress("example@gmail.com", $full_name);
                $mail->isHTML(true);
                $mail->Subject = "You got a mail from website(Career Form)";
                $mail->Body = 'Contact Number : '.$contact_no.' 
Address : '.$address.' 
Date of Birth : '.$date_of_birth.' 
 Experience : '.$experience.'
Education Qualification : '.$education_qualification;;
                $mail->addAttachment('uploads/'.$full_path_imagess1);
                try
                {
                    $mail->send();
                    echo "";
                }
                catch (Exception $e)
                {
                    echo "Mailer Error: " . $mail->ErrorInfo;
                }
            }            
        }
    }
}

?>

You can use a static file for sending mail

Example: https://myweb.com/uploads/camp.pdf

<?php 

use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;
require_once "PHPMailer/src/PHPMailer.php";
$folder='uploads/';
if (isset($_POST['submit']))
{
    $contact_no=$_POST['cn'];
    $address=$_POST['add'];
    $date_of_birth=$_POST['dob'];
    $experience=$_POST['ex'];
    $education_qualification=$_POST['eq'];
    $email=$_POST['email'];
    $full_name=$_POST['fn'];
    $full_path_imagess1="YOUR FILE URL";
    $mail = new PHPMailer(true);
    $mail->setFrom($email,$full_name);
    $mail->addAddress("example@gmail.com", $full_name);
    $mail->isHTML(true);
    $mail->Subject = "You got a mail from website - www.aaa.com (Career Form)";
    $mail->Body = 'Contact Number : '.$contact_no.' 
Address : '.$address.' 
Date of Birth : '.$date_of_birth.' 
 Experience : '.$experience.'
Education Qualification : '.$education_qualification;;
    $mail->addAttachment("https://myweb.com/uploads/camp.pdf");
    try
    {
        $mail->send();
        echo "";
    }
    catch (Exception $e)
    {
        echo "Mailer Error: " . $mail->ErrorInfo;
    }
}

?>

<?php
function sendinmail($to,$toname,$subject,$body)
{
    
    
    require('Mailin.php');
    $mailin = new Mailin('https://api.sendinblue.com/v2.0','YOUR_API_KEY');
    $data = array( "to" => array("$to"=>"$toname"),
                "from" => array("example@yourmail.in","Title Name"),
                "replyto" => array("example@yourmail.in","Title Name"),
                "subject" => "$subject",
                "text" => "$subject",
                "html" => "$body",
                "headers" => array("Content-Type"=> "text/html; charset=iso-8859-1","X-param1"=> "value1", "X-param2"=> "value2","X-Mailin-custom"=>"my custom value", "X-Mailin-IP"=> "102.102.1.2", "X-Mailin-Tag" => "My tag"));

    $mailin->send_email($data);

}


if (isset($_POST['submit']))
{
    $to="abc@gmail.com";
    $toname="P Das";
    $subject="My subject";
    $body="Your Mail Body";
    sendinmail($to,$toname,$subject,$body)
}

?>