add action hook so we can save the messageid after the email is sent

[aytackokus]

This is an enhancement for the issue #22

This feature will allow us to save MessageID after the email is sent.

If you want to save the MessageID to a POST, then you need to add the post id to the $headers argument of wp_mail function. This will not create any malfunctions with email part, because the headers does get filtered to a new variable ($recognized_headers).

For example:
$headers['post_id'] = $post_id;

Arguments sent with the hook:
$response = response from postmarkapp API
$headers = headers from wp_mail function

So after the email is sent, we can catch the response_data by adding an action hook.
add_action('postmark_response', 'handle_postmark_response', 10, 2);

function handle_postmark_response($response_data, $headers) {
$response_data = json_decode($response_data['body']);
$post_id = $headers['post_id'];
$message_id = $response_data->MessageID;
}

[atheken]

@aytackokus - This is really great. Since I'm not a wordpress guru, I've struggled with how best to provide this feedback, without breaking the wp_mail convention. This is a really elegant solution to that problem. I think it could also make sense to emit a hook for sending errors. What do you think?

[aytackokus]

@atheken Thanks. I think adding a hook for sending errors is a nice to have feature.

[aytackokus]

@atheken do you want me to add it? or will you do it?

[atheken]

@aytackokus If you have time to take a crack at it, I would appreciate it.

[aytackokus]

@atheken it is done!

[aytackokus]

Hello @atheken, when will you push this changes to the plugin?