Make hostname and HELO configurable

It needed some lines in hook_uninstall().

+++ b/smtp.admin.inc
@@ -171,6 +171,23 @@ function smtp_admin_settings() {
+  $form['client']['smtp_client_hostname'] = array(
+    '#type'          => 'textfield',
+    '#title'         => t('Hostname'),
+    '#default_value' => variable_get('smtp_client_hostname', ''),
+    '#description'   => t('The hostname to use in the Message-Id and Received headers, and as the default HELO string. Leave blank for using %server_name.', array('%server_name' => isset($_SERVER['SERVER_NAME']) ? $_SERVER['SERVER_NAME'] : 'localhost.localdomain')),
+  );
+  $form['client']['smtp_client_helo'] = array(
+    '#type'          => 'textfield',
+    '#title'         => t('HELO'),
+    '#default_value' => variable_get('smtp_client_helo', ''),
+    '#description'   => t('The SMTP HELO/EHLO of the message. Defaults to hostname (see above).'),
+  );

Array are not according with drupal 8 codding standars.
https://www.drupal.org/coding-standards#array

Updated per #6.

@arnested ok. It's a good reason :=)

I didn't check others arrays in the module but I hate this style (it's a personal war) and while I was reviewing I saw it and... I had to told it. XD

Anyway now have both patches, mantainers can decide to use the first or the second one.

Thank for explain it :)

Closed a duplicate: #2287825: Using SMTP Mail with Office365

This should be safe to include in the next release.

Thank you thank you. I use a custom tld (.dev) in my local development environment which is rejected by smtp.gmail.com, so this is a big help.

Tested and working for me in 7.x-1.3.

Per all discussion and review above, @arnested's note in #15, and @DamienMcKenna's note in #12, I'm going to change the status.

This patch is not currently applying, could someone please re-roll it?

I did a quick merge from #19 to the new branch I created today with the changes we were working for #1705764: Support for multiple SMTP credentials/servers but I think the proper way to handle this would be to move the smtp_client_hostname and smtp_client_helo to be defined by SMTP provider.

Marking this as to be ported so we don't forget about working on this.

Here is an attempt to port this feature to 8.x branch.

Thanks!