Contact Form doesn't send mail - php

Question

I have a problem. Today I made contact form but it is not sending any emails and I don't know why. I downloaded an free example and I tried to add it to my own site but it's not working, any ideas? Here is the code:
<form id="contact-form" class="wniosek" action="wyslijWniosek.php" method="POST">
<div class="col-sm-4">
<label class="firma rel col-sm-12"><span class="inp"><input name="firma" type="text" placeholder="Nazwa Firmy" class="col-sm-12"></span></label>
</div>
<div class="col-sm-4">
<label class="name rel col-sm-12"><span class="inp"><input name="name" type="text" placeholder="Imie i nazwisko" class="col-sm-12"></span></label>
</div>
<div class="col-sm-4">
<label class="phone rel col-sm-12"><span class="inp"><input name="phone" type="text" placeholder="Telefon" class="col-sm-12"></span></label>
</div>
<div class="col-sm-4">
<label class="email rel col-sm-12"><span class="inp"><input name="email" type="text" placeholder="E-mail" class="col-sm-12"></span></label>
</div>
<div class="col-sm-4">
<label class="kwota rel col-sm-12"><span class="inp"><input name="kwota" type="text" placeholder="Prognozowana Kwota" class="col-sm-12"></span></label>
</div>
<div class="col-sm-4">
<label class="wnio col-sm-12">
<select name="wnio" style="width:100%;">
<option value="kfirm">Kredyt Firmowy</option>
<option value="kgot">Kredyt Gotówkowy</option>
<option value="kobro">Kredyt Obrotowy</option>
<option value="phipo">Pozyczka Hipoteczna</option>
<option value="khipo">Kredyt Hipoteczny</option>
<option value="kkonso">Kredyt Konsolidacyjny</option>
<option value="kinwest">Kredyt Inwestycyjny</option>
<option value="ksamocho">Kredyt Samochodowy</option>
<option value="leasing">Leasing</option>
</select>
</label>
</div>
<div class="col-sm-12">
<label class="message rel col-sm-12"><span class="text_a"><textarea name="message" class="col-sm-12" placeholder="Wiadomosc" style="height:300px;"></textarea></span></label>
</div>
<div class="col-sm-4">
<div class="buttons-wrapper">
<input class="button2 btn btn-white" type="submit" value="Send">
<input class="button2 btn btn-white" type="reset" value="Clear">
</div>
</div>
</form>
and php:
<?php
$firma = $_POST['firma'];
$name = $_POST['name'];
$email = $_POST['email'];
$phone = $_POST['phone'];
$wnio = $_POST['wnio'];
$kwota = $_POST['kwota'];
$message = $_POST['message'];
$formcontent=" Nazwa Firmy: $firma \n Imie i Nazwisko: $name \n Email: $email \n Telefon: $phone \n Wniosek: $wnio \n Prognozowana Kwota: $kwota \n Wiadomość: $message";
$recipient = "<mail here>";
$subject = "Formularz Kontaktowy";
$mailheader = "Wiadomość ze strony internetowej";
mail($recipient, $subject, $formcontent, $mailheader) or die("Błąd!");
echo "Dziękujemy!" . " -" . "<a href='form.html' style='text-decoration:none;color:#ff0099;'> Return Home</a>";
?>
where is mail here i put my own email

Answer 1

Please replace mail($recipient, $subject, $formcontent, $mailheader) or die("Błąd!"); with below code.
$suc = mail($recipient, $subject, $formcontent, $mailheader);
if($suc){//If success
print_r("No error");
}
else{//If error on mail send
print_r(error_get_last());
}
exit();//Remove this after debugging done
If mail() not delivered successfully this code will print error into array format, else it would print 'No error'.
Let us know if you face any further query regarding the same.

Answer 2

You have to set the sender e-mail in your header.
$mailheader = "From: sender#mail.com";