Send email with PHPMailer over SMTP

Use PHPMailer's SMTP mode to deliver through Unitpost from plain PHP. Port 587 with STARTTLS; don't use port 25.

1. 1

   Install PHPMailer

   Add it via Composer.

   Shell

   composer require phpmailer/phpmailer

2. 2

   Configure and send

   Set PHPMailer to SMTP mode with your Unitpost credentials.

   PHP

   <?php
   use PHPMailer\PHPMailer\PHPMailer;
   
   $mail = new PHPMailer(true);
   $mail->isSMTP();
   $mail->Host       = "smtp.unitpost.com";
   $mail->SMTPAuth   = true;
   $mail->Username   = "unitpost";
   $mail->Password   = getenv("UNITPOST_API_KEY");
   $mail->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;
   $mail->Port       = 587;
   
   $mail->setFrom("you@yourdomain.com", "Your App");
   $mail->addAddress("customer@example.com");
   $mail->isHTML(true);
   $mail->Subject = "Hello from Unitpost";
   $mail->Body    = "<h1>Welcome!</h1><p>Sent via SMTP.</p>";
   $mail->send();

3. 3

   Verify delivery

   The message appears in your Unitpost Activity view with full tracking.