queries regarding PHP mail() 'issues' - php

Question

So I recently made a basic site for a family members small company. I included a mail form, for enquiries etc.
here is the code i use:
<?php
function check_input($data){ // SANITIZE USER STRING INPUT
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
return $data;
}
$name = check_input($_POST['name']);
$surname = check_input($_POST['surname']);
$email = check_input($_POST['email']);
$telephone = check_input($_POST['telephone']);
$comments = check_input($_POST['message']);
$message = "From: $name $surname
Email: $email
Telephone: $telephone
--------------------------------------------------------------
Comments: $comments
";
mail("#############.com","Website Enquiry from www.#######.co.uk",$message,"From: webserver");
?>
now when I try it, it works absoloutely fine. However I have noticed sometimes it is realllllly slow and so we have been receiving blank emails through the form (the user input data is not present), so it appears someone has attempted to use it and given up perhaps because it is taking too long?
I am assuming this is to do with the mail server rather than php mail. But I wanted to see if anyone could highlight potential issues that I could take to the company hosting for her?
many thanks,

Answer 1

check if name and email fields are entered and then proceed with mail function..this reduces getting blank emails.
<?php
if (isset($_POST['name']) && isset($_POST['email'])) //check if name and email fields are entered and then proceed with mail function
{
//process the data and send mail.
}
else
{
echo "Error missing name or email field.please enter";
}
?>
Alternatively you can also use array_key_exists()
<?php
if (array_key_exists("name", $_POST) && $_POST["name"] != "" && array_key_exists("email", $_POST) && $_POST["email"] != "")
//check if name and email fields are entered and then proceed with mail function
{
//process the data and send mail.
}
else
{
echo "Error missing name or email field.please enter";
}
?>

Answer 2

Actually you are not checking if someone fill the form empty that's why you are getting blank fields
<?php
function check_input($data){ // SANITIZE USER STRING INPUT
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
return $data;
}
if(!empty($data))
{
$name = check_input($_POST['name']);
$surname = check_input($_POST['surname']);
$email = check_input($_POST['email']);
$telephone = check_input($_POST['telephone']);
$comments = check_input($_POST['message']);
$message = "From: $name $surname
Email: $email
Telephone: $telephone
--------------------------------------------------------------
Comments: $comments
";
mail("#############.com","Website Enquiry from www.#######.co.uk",$message,"From: webserver");
}
?>