I might be able to provide some help for the third option, using HTTP Post, since I did implement it once in a project.
First, I used this nice and simple iOS class to take care of the posting for me.
Then, the following iOS code snippet should show you how it's done
NSString* from = @"sender@email";
NSString* to = @"receiver@email";
NSString* mailCc = @"cc@email";
NSString* message = @"my message"
NSString* subject = @"my subject";
NSURL* url = [NSURL URLWithString:@"http://yourtestsite.com/my_email_script.php"];
//these are $_POST variables sent, so 'from' would be $_POST['from']
NSArray *keys = [[NSArray alloc] initWithObjects:@"from", @"to", @"cc", @"subject", @"message", nil];
NSArray *objects = [[NSArray alloc] initWithObjects:from, to, mailCc, subject, message, nil];
NSDictionary *dictionary = [[NSDictionary alloc] initWithObjects:objects forKeys:keys];
NSMutableURLRequest* request = [SimplePost urlencodedRequestWithURL:url andDataDictionary:dictionary];
NSURLResponse* response = [[NSURLResponse alloc] init];
NSError* error = [[NSError alloc] init];
NSData *returnData = [NSURLConnection sendSynchronousRequest: request returningResponse: &response error: &error];
NSString* result = [[NSString alloc] initWithData:returnData encoding:NSStringEncodingConversionAllowLossy];
//I'm checking for 1 because my php script was set to write 1 to the page in case of success and 0 otherwise, so this is simply my implementation
if([result isEqualToString:@"1"]) {
NSLog(@"success");
} else {
NSLog(@"error");
}
For the PHP file, this should do the trick
$from = filter_var($_POST['from'], FILTER_SANITIZE_EMAIL);
$to = filter_var($_POST['to'], FILTER_SANITIZE_EMAIL);
$cc = filter_var($_POST['cc'], FILTER_SANITIZE_EMAIL);
$subject = htmlspecialchars(utf8_decode($_POST['subject']));
$message = utf8_decode($_POST['message']);
// To send HTML mail, the Content-type header must be set
$headers = 'MIME-Version: 1.0' . "\r\n";
$headers .= 'Content-type: text/html; charset=iso-8859-1' . "\r\n";
// Additional headers
$headers .= 'From: ' . $from . "\r\n";
$headers .= 'Cc: ' . $cc . "\r\n";
// Mail it
if(mail($to, $subject, $message, $headers)) {
echo("1");
} else {
echo("0");
}
Keep in mind, I'm no PHP expert, so that code might be improved, especially on the security part.
[edit]
PHP mailing should already be enabled in most major managed hosting solutions, be it a cheap shared account, a VPS or a dedicated server. But if you plan to send A LOT of emails with this method, then a dedicated server is recommended.
However, there is a limit of emails you can send and better options than the mail function. You can find more info about this here.
[later edit]
It seems the author deleted the SimplePost class. However, the same author made an alternative which should help, called SimpleHTTPRequest. The rest should remain the same
