IMAP section in the Gmail example (PHPMailer#1117)

Add IMAP example into gmail example

examples/gmail.phps

@@ -1,6 +1,7 @@
 <?php
 /**
  * This example shows settings to use when sending via Google's Gmail servers.
+ * The IMAP section shows how to save this message to the 'Sent Mail' folder using IMAP commands.
  */
 
 //SMTP needs accurate times, and the PHP time zone MUST be set
@@ -72,4 +73,27 @@ if (!$mail->send()) {
     echo "Mailer Error: " . $mail->ErrorInfo;
 } else {
     echo "Message sent!";
+    //Section 2: IMAP
+    //Uncomment these to save your message in the 'Sent Mail' folder.
+    #if (save_mail($mail)) {
+    #    echo "Message saved!";
+    #}
+}
+
+//Section 2: IMAP
+//IMAP commands requires the PHP IMAP Extension, found at: https://php.net/manual/en/imap.setup.php
+//Function to call which uses the PHP imap_*() functions to save messages: https://php.net/manual/en/book.imap.php
+//You can use imap_getmailboxes($imapStream, '/imap/ssl') to get a list of available folders or labels, this can
+//be useful if you are trying to get this working on a non-Gmail IMAP server.
+function save_mail($mail) {
+    //You can change 'Sent Mail' to any other folder or tag
+    $path = "{imap.gmail.com:993/imap/ssl}[Gmail]/Sent Mail";
+
+    //Tell your server to open an IMAP connection using the same username and password as you used for SMTP
+    $imapStream = imap_open($path, $mail->Username, $mail->Password);
+
+    $result = imap_append($imapStream, $path, $mail->getSentMIMEMessage());
+    imap_close($imapStream);
+
+    return $result;
 }