My SMTP Email Send Always in SPAM - email

Question

Im developing a website wherein you can inquiry our ask question via email. every time i send it, it always goes to spam
here is my code:
$fname = $_POST['fname'];
$lname = $_POST['lname'];
$phone = $_POST['phone'];
$city = $_POST['city'];
$QuestionComment = $_POST['comments'];
$hear = $_POST['about_us'];
$email_address = $_POST['email'];
// the first email is for thank you! email
date_default_timezone_set('Asia/Manila');
$mail = new PHPMailer();
$body = "Hi,<br /> <br />Thank you for contacting Magosaburo Philippines. <br />Please await for a confirmation email regarding your reservations and other concerns.";
$mail->IsSMTP(); // telling the class to use SMTP
$mail->Host = "mail.magosaburo.com.ph"; // SMTP server
$mail->SMTPDebug = 2; // enables SMTP debug information (for testing)
// 1 = errors and messages
// 2 = messages only
$mail->SMTPAuth = true; // enable SMTP authentication
$mail->Host = "mail.magosaburo.com.ph"; // sets the SMTP server
$mail->Port = 25; // set the SMTP port for the GMAIL server
$mail->Username = "//dont mind it"; // SMTP account username
$mail->Password = "//dont mind it"; // SMTP account password
$address = $email_address;
$mail->AddAddress($address);
$mail->Subject = "Thank you from Magosaburo";
$mail->AltBody = "To view the message, please use an HTML compatible email viewer!"; // optional, comment out and test
$mail->SetFrom('send_mail#magosaburo.com.ph', 'Magosaburo');
$mail->AddReplyTo("send_mail#magosaburo.com.ph",'Magosaburo');
$mail->MsgHTML($body);
if(!$mail->Send())
{
echo "Mailer Error: " . $mail->ErrorInfo;
}
else
{
echo "Message sent!";
}
Im new in php email sending i dont know how or why it goes to spam. thank you!

Answer 1

Use a DK/DKIM signature in your mail, that might help.

Answer 2

If it's just gmail that's categorizing you as spam you may be on their blacklist, here's some info on getting off that. Then there's headers, there's an example of headers in action on this SO post. And finaly, on an email by email basis there's a few additional tips here.
Summary: 1. Check if you're IP is actually on google's spam list. 2. Use headers so provide filters with a more complete information on your emails. 3. Address any potential "spammy looking" content.
Good luck!

Answer 3

Its because of the fact that. The email providers have their own preferences about the email senders.
If the server from which you send emails is based on a malware. The email company will block them. Basically because the user has already marked the server as Spam. And the new emails are sent to the Spam!
Try adding some more information. Like a signature. Or try to read their user guides on how to remove or send a request to the email service to check that the emails you send are not malware!