Add "Reply-to" field to Rules and system actions

Do you mean to allow to set a Reply-To address for the Rules actions? If you are using Mime Mail within a custom module you can add the Reply-To header manually.

Changing issue settings.

Having this feature would be very helpful for us as well.

Attached patch adds a reply-to parameter to the mimemail rules action.
Further it generalizes the address header handling.

Use-case for the reply-to for us is that our customer gets notifications about commerce orders.
The notification uses the shop-customers mail address as sender, that way the booking-agents can reply directly to the notification mail.
"Unfortunately" our customer has a restrictive mail-server that checks if a sender mail address is valid.
That means if the shop-customer inadvertently enters an invalid mail-address the booking-agents won't get the notification and thus don't have a chance to act as quick as normal.
Adding the reply-to header could solve this issue by still allowing the agents to reply directly to the notification mail.

@das-peter: Patch looks good, thank you! Would you do the same for the system actions as well and attach a new patch including that too?

@sgabe: Thank you for the feedback. Here's the extended patch.
I did also some cleanup using drupalcs - the second attached patch (mimemail-coding-standards-cleanup.patch) contains these changes and could be applied after the reply-to patch is applied.

+++ b/modules/mimemail_action/mimemail_action.module
@@ -136,6 +144,11 @@ function mimemail_send_email_action_validate($form, $form_state) {
+  $reply_to = trim($form_state['values']['$reply-to']);

This line will throw an error because of the variable prefix in the index.

Otherwise it looks good, but we should also have a back port to D6.

+++ b/mimemail.module
@@ -326,22 +332,20 @@ function mimemail_mail($key, &$message, $params) {
+    'bcc' => 'Ccc',

Here the header should be Bcc.

I am attaching new patches for D6 and D7.

@sgabe: Sorry for the sloppy copy/paste (['$reply-to'] and thank you very much for your effort!

Would be appreciated if you could test it.

Patches need to be rerolled.

Rerolled and committed to both branches.